MacOS Sequoia installed. Internet will randomly drop connection

I was able to "fix" my network issues by disabling the microsoft content filter in Settings --> Network --> Filters.

Might work for content filters of other brands too.

Firewall is still enabled.

As I noted in another thread, this is a widely reported bug in Sequoia (just google intermittent internet connection Sequoia). As stated, on that thread and here, turning off the built-in firewall usually works, it did on my 2019 intel imac and 2023 mac M2 studio. If you have a managed mac and cannot turn of firewall no good options that I know of. Interestingly, the packet filter (PF) firewall app MURUS works just fine on both my computer's but not the built-in firewall setting when enabled. Curious since Murus is just a GUI app for macOS built-in PF firewall.

Hello,

I hope this post helps the Apple team fix the Wi-Fi issues introduced with Sequoia.

I have an Apple M3 Max MacBook Pro. I was running Sequoia 15.1 and had been experiencing intermittent internet issues, such as "Unstable Network" during Zoom calls, dropped Zoom calls, and slow YouTube streaming. I do not experience these issues before upgrading to Sequoia. I had never considered that the Mac OS would be at fault.

Yesterday I updated to Sequoia 15.2 hoping to resolve (some of) these issues. The result was the oposite. Before the update, my Wi-Fi was limping but moving. After the update, I lost Wi-Fi functionality.

Below is an image from SpeedTest.Net comparing the before (limping network: 250-400 Mbps) to the after upgrade (unstable and unreliable network), where the lowest download and upload speeds I got were 12 Mbps and 0.02 Mbps, respectively (not in image below).

To determine the origin of the issue, I tested the modem/router speed. It also uses SpeedTest.net (below) and it showed the stable and consistent download speeds of <500 Mbps I have had since forever. Spectrum's upload speeds have never been great, but I care more about downloads.

Then, to test the Wi-Fi network, I used SpeedTest.net on my iPhone 16 Pro running iOS 18.1.1, and the speeds were and still are in the >435 Mbps. I obtained similar numbers with my daughter's Chomebooks, and other family phones.

Together, these data strongly suggests that the issues are on the WiFi configuration in the Sequoia operating system. I searched on Google for potential solutions discussed by other Mac owners, and some things helped, other maybe helped, and most did not matter.

Things that helped:

• • Forget the Wi-Fi and use a wired connection instead - HELPED
  • Turn off the "Apple Network Firewall"
    • Turning off the "Apple Network Firewall" is absolutely required if you want to use a VPN with a wired connection. If you do not plan to use a VPN, you can leave the "Apple Network Firewall" on
    • Turning off the "Apple Network Firewall" significantly hepled Wi-Fi functionality

Things that might have helped:

• • Turning off the VPN
  • Turning off iCloud "Private relay"
    • NOTE: in a wired connection without Firewall and with VPN, turning on the "Private relay" has minimal impact on speed
  • The "Limit IP address tracking" toggle switch
  • Adding the 8.8.8.8, 8.8.4.4, 1.1.1.1, 1.0.0.1 DNS servers
    • NOTE: in the wired connection I am still using the DNS server from my router/modem, which I am getting automatically from Spectrum; so it is very unlikely that addidng these DNS servers had major impact
  • Changing the Wi-Fi MTU from standard/auto (1,500) to 1,453
  • Disabling "20/40 MHz Coexistence" in my modem/router

Things that did not matter:

• • Uninstalling Sophos antivirus to remove content filters, but it dod not have any impact, so I reinstalled it
  • Rebooting the router/modem
  • Forgetting the network and re-signing in
  • Cleaning the DNS cache
  • Using a fixed IP address
  • Changing the channels for 2.4GHz and 5GHz
  • Renewing the DHCP lease
  • Deleting the files below from the /Library/Preferences/SystemConfiguration folder and rebooted the Mac

• • Rebooting the computer as follows
    • Simultaneously pressing shift + ctrl + cmd + ON_button for 10 seconds
    • Pressing the ON_button imediately followed by simultaneously pressing option + cmd + P + R

The final diagnostic run by the Wireless Diagnostic app is below.

Please let me know if there is anything esle you may need to unravel this problem to fix it ASAP, as many of us rely on Wi-Fi for our day-to-day work.

Thank you.

All the best,

Andres

I turned off the rotating MAC address, a stupid idea to start with, as it messes up cached ARP entries on OTHER devices. I deleted little snitch (which was a major source of the headaches). I used Wireshark to note that the default internal firewall ruleset blocks DNS _replies_, even though the state table was supposed to be set up on the outbound query. Nope. The nasty part is this is random, it works for a while, then it doesnt. So... the Firewall Control Panel entry is not reflecting the true pass/block rules right ? I turned off Intego Netbarrier too, as it is conflicting with some state (who knows what) in the network stack of the os. I am very familiar with pf, so I went in and added an explicit pass rule for DNS inbound/outbound to /etc/pf.conf. Be careful if you dont know what you are doing ! Here's how you prove it, do a dig or nslookup and it wont work until you modify the pf.conf and reload pf. Fixed. It was so broken out of the box that trying to do a 'Software Update' check was failing with "no network connection". I hate lousy error messages like this that dont REALLY tell you anything. The NETWORK connection is not failing, it is DNS inbound which is being blocked, so the calling app hangs. This is another bug, it should time out and give an error "DNS timeout". So 'splain me dis Ricky, why when you try to disable the firewall, it hangs all network interfaces ?

After lots and lots of testing and trying things, I found out the following:

• WIFI works now with private static MacAddress
• Private Relay is not an issue
• LittleSnich works fine

Ethernet, on the other hand, had a totally new issue introduced here for me: I had to switch the Hardware settings from "Automatic" to "Manual". As soon as I switch on auto negotiation, problems re-occur.

Maybe that helps someone.

Thanks, this worked!!!

I had trouble with older LittleSnitch on my system after upgrade to Sequoia 15.0.1.

My wifi was locked out, no network access (I don't have ethernet cable handy either to connect to the iMac.)

And I could not airdrop a new DMG file from other machines.

First, I made sure to stop backup in progress.

After going to Network -> Settings -> Filters, I saw that LittleSnitch was disabled.

Enabled, everything network came back, transferred DMG file and got updated, problem gone.

my problem was an incompatible little snitch version after the update. same thing: worked for 30sec and then all traffic was blocked. in any case, check your vpn settings for tools that might be incompatible

In Disk Utility>View, select Show all Devices, highlight the top left entry.

Run Disk First Aid on all items in the left panel, from top down.

Are you running any VPN, Anti-Virus, or Cleaning apps?

We need to see what all is running, a report from this will not display any personal info...

Using EtreCheck - Apple Community

EtreCheck is a FREE simple little diagnostic tool to display the important details of your system configuration and allow you to copy that information to the Clipboard. It is meant to be used with Apple Support Communities to help people help you with your Mac. It will not display any personal info. Give it Full Disk Access.

https://www.etrecheck.com/

Give etrecheck Full Disk Access before running.

Thanks for Old Toad’s etrecheck instructions…

Slow iMac 2017 - Apple Community

I turned off the rotating MAC address, a stupid idea to start with, as it messes up cached ARP entries on OTHER devices. I deleted little snitch (which was a major source of the headaches). I used Wireshark to note that the default internal firewall ruleset blocks DNS _replies_, even though the state table was supposed to be set up on the outbound query. Nope. So... the Firewall Control Panel entry is not reflecting the true pass/block rules right ? I turned off Intego Netbarrier too, as it is conflicting with some state (who knows what) in the network stack of the os. I am very familiar with pf, so I went in and added an explicit pass rule for DNS inbound/outbound to /etc/pf.conf. Be careful if you dont know what you are doing ! Here's you you prove it, do a dig or nslookup and it wont work until you modify the pf.conf and reload pf. Fixed. It was so broken out of the box that trying to do a Software Update check was failing with "no network connection". I hate lousy error messages like this that dont REALLY tell you anything. The NETWORK connection is not failing, it is DNS inbound which is being blocked, so the calling app hangs. This is another bug, it should time out and give an error "DNS timeout".

Hello,

I have an Apple M3 Max and was using Sequoia 15.1. I had been experiencing intermittent Wi-Fi issues ("Unstable Network" errors) during Zoom calls, so I decided to "fix them" by upgrading to Sequoia 15.2.

The update has been disastruous. Below you can see the Speedtest results before and after the update. My Wi-Fi downloads have dropped to as low as 26 Mbps (see below) and my upload speeds to as low as 0.02 Mbps. It is extremely unstable.

To ensure that the Wi-Fi issues were on the Mac and not on other devices, I first tested the speed at the modem/router, which has been ~500 Mbps since forever.

Then, I did the same on my iPhone 16 Pro (iOS 18.1.1) connected to the Wi-Fi, which has been > 450 Mbps since forever.

To improve stability and connectivity, I followed a number of suggestions I found online, which may have helped, although it hard to say based on the observed fluctuations (see the first image above).

• I turned off the following:
  • My VPN
  • The iCloud Private Relay
  • The Firewall
  • The "Limit IP address tracking" toggle shitch
• I configured the MTU manually to 1,453
• I added the 8.8.8.8, 8.8.4.4, 1.1.1.1, and 1.0.0.1 DNS servers

Before Sequoia I did not need to make any of these changes and my Wi-Fi was stellar.

I also uninstalled the Sophos antivirus, in case the content filters were impacting Wi-Fi speeds, which made no difference, so I reintalled it.

In addition, I:

• Use no Proxies
• Rebooted the modem/router
• Renewed the DHCP leases
• Flushed the DNS cache
• Turned the Wi-Fi Off and On
• "Forgot the Network" and installed it again
• Deleted the files below and restarted the machine
  • com.apple.airport.preferences.plist
  • com.apple.network.eapoclient.configuration.plist
  • com.apple.wifi.message-tracer.plist
  • Networkinterfaces.plist
  • preferences.plist
• I restarted the machine as follows:
  • Simultaneously press: shift + ctrl +cmd + ON button for 10 seconds
  • Press ON, then simultaneously press option + cmd + P + R for 20 seconds
• Have run the "Wireless Diagnostics" app. Below is the latest run after all the improvements.

I have done combinations of the above in different orders to no avail. The Wi-Fi is unstable and not even half as powerful as it once was.

I am hoping that wired connectivity will not suffer similarly. But, if this is the case, I will update my post once I test it.

Please let me know if you will need any other type of information to assist in resolving this situation. Like others in this thread, we depend on our use of Wi-Fi for our day-to-day work and need to have this issue sorted out ASAP.

Thank you.

All the best,

Andres

Hi,

For several weeks now we've been having problems with instabilities between MacOS Sequoia and GlobalProtect (Tip: migrate to GP V6.2.6 which is supported by SEQUOIA). Our MACs randomly lose the internet connection often after a reboot or startup. We finally have a solution that seems to make the Internet connection stable. Since installing MacOS 15.2 I've been unable to cause the problem on my MAC. I strongly advise you to install Mac OS Sequoia 15.2 and test it.

I had same identical problem. I turned off firewall and Safari came back up. Once it looked like things were stable i restarted firewall. I'm hoping I keep on. Went and ordered adapter to direct connect to my router - maybe I should've waited :). Anyway hope this helps. i used Private = rotating and Limit IP address tracking. i know a lot of folks are using VPN and i'm not so not sure if this will fix that problem.

Tsinoy Newbie wrote:

Basically removed little snitch adguard and vpn configurations first. Will let it sort through everything and settle before adding them back one by one

Unless you're using a true VPN tunnel, such as between you and your employer's, school's or bank's servers, they provide false security from a privacy standpoint.  Read these articles:  Pubic VPN's are anything but public and Security Risks: The Dangers of Using Free VPNs (eccu.edu).  

Also, Little Snitch isn't necessary. It can only use up system resources. Additionally, there's no need to ever install and run any "cleaning", "optimizing", "speed-up" or anti-virus apps on your Mac?

Also make sure you aren't running any VPN. Disable any firewalls or other 3rd party "security" apps.