How to Fix Apps Not Working on Cellular Data After iOS 18 Update?

I had the same issue but I fixed it by resetting Cellular Data Network with my network provider username and password. Go ahead and try it. It worked for me.

I had the same issue but I fixed it by resetting Cellular Data Network with my network provider username and password. Go ahead and try it works.

I have a problem that I believe is the same as the OP. iPhone 14 Pro, recently updated to iOS 18. Here's the behavior I'm seeing: For all the apps listed in Settings > Cellular > Show All

• If Cellular Data was ON (green) before the upgrade, and I turn it OFF (grey), it will revert to ON as soon as I leave the settings screen (e.g. to return to the app)
• If Cellular Data was OFF (grey) before the upgrade, and I turn it ON (green), it will revert to OFF as soon as I leave the settings screen

In other words, all apps listed in Settings > Cellular > Show All are stuck in whatever they were set to before the upgrade. The toggle buttons can be moved, but the new setting won't take hold. The short list of apps in Settings > Cellular (i.e. not under Show All) can be toggled on and off as expected.

Turn off RCS

Turn off RCS

Try switching to 4 g cell network

Kind of the same here. After updating, the Meross app which controls my smart plugs, the Kasa app that controls my security camera, the Cloudedge app that controls my doorbell camera and the app that controls my Oasis Mini are all bricked. The smartplugs still work in their basic form but they are unresponsive and unable to be re-added to homekit. The app throws an error when trying to add them back in. The Kasa app shows no items available to add. I’ve tried to re-add my doorbell camera and it’s unresponsive as is the same with my Oasis Mini. I’ve reset network connections, restarted my phone as well as restarting my router…nada. I wish there was an easy way to go back to 17 until they have these issues sussed out.

Same for me - I deleted some apps and put them back and they worked. But so many things don't. My Music library is screwed and won't sync properly anymore, I can;t play my music in the car - it will not come through the speakers - the list goes on. What are we supposed to do?

I have an IPhone 14 (regular) and ever since ios 18 my phone has been slower than ever when I’m out of home using cellular and EVEN at home using wifi. I’m very relieved that I am not the only one and that it very much IS ios 18 that is causing the issue in general. I tried updating my phone to ios 18.01 but i think load times got even worse. Apple please fix this as soon as possible, i cannot contact people because apps are completely unusable.

I have iPhone SE 3rd gen and after the latest 18.0.1 update half my apps won’t work with my cell data only in WiFi I’ve reset my phone to factory even bought a new sim chip thinking that was it but it’s not it’s the update it stoped working right after the update 18.0.1 it fine on the 18.0 update

you gotta turn off rcs

IOS 18 Safari on Mobile data netwo… | Apple Developer Forums

similar kind of thread in developer community.

Kind of same here. I am on I phone 12 pro and after iOS 18 update, my phone can't connect on wifi and mobile data. I've tried all the recommends that i've read on internet about How to Fix iOS 18 Wifi Issues etc but nothing works for me.

Yep me too. They should have never released iOS18 it’s absolutely terrible.

None of my apps work when I’m in the store. They bricked CVS, Walmart, Target, etc. Can’t look up anything and can’t pay using the app so you can skip the lines.

And don’t even get me started on the fact that iTunes, Messages, or Siri no longer works in the car while using Apple Car Play, or the fact they killed off half the Widgets I had before the upgrade.

Like Apple did you even Test this release before you released it??? As an investor in this company I’m acutely worried about the lack of quality control and testing.

Isn’t the point of beta to make sure it’s ready for release? I’ve never had so many problems with a iOS release. iPhone 15 promax… I can even get notifications from some apps that I can’t actually open to view.