iOS 26.4 causing serious issues (battery drain, Wi-Fi problems, overheating)

You aren't speaking with Apple here. This is a user to user only forum, which Apple neither participates, nor reads for user feedback.

While I have no doubt you are having issues, it's not likely caused by iOS 26. There are millions upon millions of people out there with iOS 26 who aren't having any issues. Like me, for example. All of our devices are updated to iOS 26, Apple WatchOS 26, iPadOS 26, MacOS 26, with zero issues.

What we need to figure out is why you are having issues.

Things which can cause issues like you're having could be a failing battery or lack of free memory. You didn't tell us what model iPhone you own, but if it's more than 2 years or so old, the battery could be failing. Open Settings > Battery > Battery Health - what is the current health listed there? If 80% or less, your battery is failing and needs to be replaced at your Apple Store Genius Bar.

Now for storage, open Settings > General > iPhone Storage - how much space do you have left on the phone. If you have less than 12GB or even lower, you need to delete things on your phone to free up space, such as Photos, Videos, Music, Apps, Messages, Email, etc.

Do you have a VPN installed on your iPhone? VPNs cause all sorts of connectivity issues and they aren't needed unless one is required by your school or employer. If you have a VPN on your phone, remove the VPN profile and any associated Apps, then follow the procedure I'm including a link to below.

Finally, after you updated your phone, did you or do you ever Force Restart it? I Force Restart after every iOS update and this procedure is recommended when you experience issues --> Force restart iPhone - Apple Support

imdad227 wrote:

Has Apple acknowledged this issue or identified the root cause? If engineering is investigating, it would be helpful to know whether this is related to Wi-Fi, power management, or networking changes introduced in the iOS 26.x releases. I would also appreciate any guidance on whether a fix is planned in an upcoming software update.

This is a user to user only forum, which no one Apple actively participates (with the exception of moderators). As users only, we have no clue what Apple may be working on. But your question assumes everyone must be having an issue which requires a solution. That would be a bad assumption as the vast majority of users aren't having such issues. I have multiple devices on iOS 26.5, none of which are having Wifi or battery drain issues. There are currently more than 2.5 Billion devices out there, used by more than 1.5 Billion users. If this was a significant issue, this forum would be flooded with people complaining, yet it's not. The tech press would be all over this, yet it's not.

You need to try to figure out what is causing issues on your device. One of the biggest causes of such issues is having a VPN installed on your phone (used or not) or cleaner apps or Anti-Virus software. None of which offer any advantage on an iPhone. In fact, they cause connectivity issues and unless required by a school or employer (who should provide the VPN) shouldn't be used.

Read this link from Apple about batteries draining faster --> If the battery in your iPhone or iPad drains too quickly - Apple Support

D_K_S wrote:

Ever since the 26.4.2 update my iPhone battery drains fast and constantly over heats and I’m not the only one having these problem!!!

“The iOS 26.4.2 update has been reported to cause overheating issues on iPhones. Users have noted that after updating, their devices experience significant temperature increases during normal use, alongside other problems like battery drain and unstable Wi-Fi connections”

🤬

Reported where? All of our devices are running iOS 26.4.2 and none of them are having any heating issues of any kind. It's common for heating to happen immediately after an update as a phone needs to spend what can be days, depending on how much data is on the device, to reindex the millions of bytes of data. Another cause can be a battery which is failing. If you open Settings > Battery > Battery Health - if the battery health is close to, at or below 80%, the battery is failing.

As to Wifi connectivity issues, is there a VPN on the phone? VPNs don't provide the security people have been led to believe they do, in fact, quite the opposite. VPNs do, however cause Wifi connectivity issues, so if you have one, get rid of it unless required by a school or employer.

Another issues can be available memory on the device. In Settings > General > iPhone Storage - how much free space is available? You should strive to have at least 10GB - 12GB available at all times. If storage is low, the phone can't operate optimally.

Updates don't typically cause connectivity or heating issues. There are too many other factors at play which need to be considered. There are literally hundreds of millions of people on iOS 26.4.2. Out of that number, there will always be a small percentage of users who have issues. That doesn't mean the vast majority of people on iOS 26.4.2 are having issues. If this was a significant issue, this forum, the most visited forum for all things iPhone would be blown up with people complaining, but it's not. The Tech Press would be all over this, but they're not.

That sounds really annoying! After updating to iOS 26.4, try a few quick fixes:

Check Battery Usage: Go to Settings > Battery and see if any app is using too much power.

Reset Network Settings: If Wi-Fi is acting up, go to Settings > General > Reset > Reset Network Settings.

Force Restart: Hold volume up, volume down, then hold the side button to restart.

Update to the Latest iOS: Sometimes these issues get fixed in minor updates, so check Settings > General > Software Update.

Low Power Mode: Turn on Low Power Mode under Settings > Battery to extend battery life while troubleshooting.

[Edited by Moderator]

imdad227 wrote:

@Apple, are you looking into this? What is breaking the connection in WiFi and causing battery to drain without the use of any Apps.

Sorry, you are not addressing Apple here as they do not participate in providing Support on this Community Forum of other Apple users and they won't see your post.

For the issues you have identified, you will need to provide additional information and I would recommend creating a new post with those details as each user may have a completely different cause to the problem.

For WiFi connectivity, that is usually due to a couple of causes:

• Your router is broadcasting a 2.4Ghz signal where you have multiple devices connected, and this legacy frequency is often not reliable due to interference and channel overlap. The solution for this is to create a 5Ghz only WiFi network on your router and connect to that network instead.
• You may have a VPN installed where users frequently find that it alters their network connections including WiFi. Uninstalling the VPN in the case would be needed as simply turning it off will not help in most cases.

For battery draining, there are a couple of things that may be helpful.

• What is your Battery Health at Settings > Battery > Battery Health? If it is below 80%, the battery needs replacing. It is only expected to last 1000 charge cycles on your phone.
• Not using an app does not mean they are not consuming your battery and most all Social Media apps use background processes that will consume your battery even when the app is not open. Meta is the worst, but there are others. Post a screenshot of Settings > Battery > View All Usage, that shows your 2 battery graphs and the top 5 apps consuming your battery.

If you prefer to seek support directly from Apple instead, then you would need to use this link to contact them.

Contact Apple Support - Apple Support

It has something to do with the backend of how iOS builds a device profile, i remember it happened long ago to one of the early iPhones too. I wouldn’t expect an Apple fix for your current hardware, restoring the phone fixed my problems.

You just need to restore your device and set it up as a new phone. You can still log in with your Apple, but not restore from backup.

"Yes, I have already submitted an official complaint to Apple and also had my device checked at a service center. I did not experience these issues on iOS 18, but they started after updating to iOS 26. The service center also mentioned that the problem is likely related to the update."

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Overheating After an Update:

IF App insists that it will be fixed in "future updates", then you may want to wait it out. In regard to the grey screen, there any bulging in the iPhone? If so, then that would indicate that the battery is corroding, and you should get this serviced, as it has become a Health Hazard.

Clear the System Data:

System Data is caches that are created by applications for embrace of usages, so that they can open quicker, and operate for sufficiently. None of this is needed. So, see about creating it all. Many out there don't realize it, but it can take up extensive amounts of storage. Use my User Tip: How to Clear "System Data" in your iPhone's Storage: - User Tip

Ever since the 26.4.2 update my iPhone battery drains fast and constantly over heats and I’m not the only one having these problem!!!

“The iOS 26.4.2 update has been reported to cause overheating issues on iPhones. Users have noted that after updating, their devices experience significant temperature increases during normal use, alongside other problems like battery drain and unstable Wi-Fi connections”

🤬

ChisolmLee15 wrote:

Regarding VPN, I find it handy for changing "my" WAN IP address - as a go around for some website challenges (Google's rCAPTCHA, Cloudflare, and some video sources).

Most will find that some simply interfere with network connections and prevent access to many servers. Apple even includes a Support Article for network issues with the first step to uninstall a VPN. If it is working for you so far, then great, and if you start experiencing Networking trouble then you will know that the first think to do is uninstall the VPN.

If your device has network connectivity issues, check for VPN and other third-party security software - Apple Support

For occasions of major iOS updates for iPhones, I fold a clean wash cloth do it is 2 layers and wrap a small "blue ice" pack (Walmart). I set the iPhone's back surface on that homemade cooler.

That keeps the phone from getting too hot.

OK. The only time you needed to be concerned that your phone is too hot is when it trips the heat sensors and you see the thermometer on the screen telling you the device is too hot and needs to cool down.

Regarding battery changes, "Apple Genius" is probably good for many iPhone users, but you can find some repair shops online, that do have very good techs and service.

Terrible advice if you want Apple to provide further service on your phone. If the provider is not an Apple Authorized Service Provider that previously serviced a phone, then Apple has refused to further service the phone. If you got an old device and you could care less if it works again and have no plans to ask Apple for service, then certainly that would be an option. If a Battery replacement is not a genuine Apple part, users have reported poor usage performance and premature failures. There are also many repair scams online, so navigating the land mine may be a challenge.

Regarding Apple's interest in this discussion forum, there are some Apple employees who keep an eye on this place - that is owned and managed by Apple.

Only Apple moderators make sure posts comply with the Terms of Use for this Support Site and follow the Community Etiquette Guidelines. Beyond that Apple will note post for any Support Question and posts are not forwarded to Apple for feedback. Many people expect that Apple is going to respond to a question or read their post for consideration of a new feature and that is not the case. Users are directed to use the Feedback link when appropriate where Apple will then read what they post.

Apple have messed up this new update has broken the 5G persistence so the phone keeps reverting to 3G and it’s causing a battery drain like I’ve not seen before

The phone is definitely overheating

It’s not just one phone I have seven phones for work Test testing Software development and all of them are doing it

I can confirm I am experiencing the exact same issue on my iPhone 15 Pro Max after updating to iOS 26.5.

Symptoms include:

• Frequent and random Wi-Fi disconnects while other devices on my AT&T Fiber network remain connected without issue.

• Significant battery drain even when no applications are running in the background.

• Increased battery usage during idle periods where the phone should be entering a low-power state.

Because every other device on my home network maintains a stable connection, this appears to point to an iOS software regression rather than a router or ISP issue. It seems possible that repeated Wi-Fi reconnect attempts or changes in the network stack are preventing the wireless radio from entering its normal power-saving mode, resulting in unnecessary battery consumption.

Has Apple acknowledged this issue or identified the root cause? If engineering is investigating, it would be helpful to know whether this is related to Wi-Fi, power management, or networking changes introduced in the iOS 26.x releases. I would also appreciate any guidance on whether a fix is planned in an upcoming software update.

I installed it yesterday and it suddenly was overheating and it could not be used for some time, a popup showed up telling me that. The phone was really hot. Battery drain was extraordinarily high, battery was dead after 3,5h after using HERE navigation system and a couple of calls

Honestly, I'm having the same issue since updating to 26.4.

I have an iPhone 17 Pro, battery health at 100%, I'm doing the optimized charging (up to 80%), etc. I noticed since upgrading to 26.4 that without even touching my phone, my battery is draining very fast!

Today I was using it very lightly, and it went from 40% to 15% in just a couple of hours. Wasn't doing that before.

I'm updating to 26.4.1 as I type. Hoping that takes care of the issue.

I keep my iPhone wall socket- charger plugged in, as often as I can.

For occasions of major iOS updates for iPhones, I fold a clean wash cloth do it is 2 layers and wrap a small "blue ice" pack (Walmart). I set the iPhone's back surface on that homemade cooler.

That keeps the phone from getting too hot.

The iPhone are encased within protective covers. So, that case plus cotton wash cloth layers = no direct contact between iPhone back and "ice."

Regarding VPN, I find it handy for changing "my" WAN IP address - as a go around for some website challenges (Google's rCAPTCHA, Cloudflare, and some video sources).

Regarding battery changes, "Apple Genius" is probably good for many iPhone users, but you can find some repair shops online, that do have very good techs and service.

Regarding Apple's interest in this discussion forum, there are some Apple employees who keep an eye on this place - that is owned and managed by Apple.