Update to iOS 26.1 once again kills cellular connectivity to t-mobile. Same situation as when 26 first got issued.
Apple Support can do nothing.
Have to speak to carrier to get the SIM updated - AGAIN.
Why can't an iOS update - that had this problem from the beginning !! - not be corrected before issuing another update? Unbelievable.
iPhone 12, iOS 26
That issue has been seen specifically with T-Mobile where service is interrupted until the Carrier Update has been applied. This is done automatically when removing/installing a SIM or manually by contacting T-Mobile directly. The Carrier Update can only be issued by the provider and are not included in iOS. Only T-Mobile would know why they need to issue the Carrier Update to maintain service where it is not needed by any other cellular provider. I think that says more about T-Mobile than it does Apple.
Don't mean to seem too critical of T-Mobile as I have them also, but it is pretty clear where you should be laying the blame.
That issue has been seen specifically with T-Mobile where service is interrupted until the Carrier Update has been applied. This is done automatically when removing/installing a SIM or manually by contacting T-Mobile directly. The Carrier Update can only be issued by the provider and are not included in iOS. Only T-Mobile would know why they need to issue the Carrier Update to maintain service where it is not needed by any other cellular provider. I think that says more about T-Mobile than it does Apple.
Don't mean to seem too critical of T-Mobile as I have them also, but it is pretty clear where you should be laying the blame.
Yes, but why does an OS update kill cellular connectivity? I've had iPhones for more than 10 years and only with iOS 26 did I have any problem with the cellular network. It really is ridiculous of Apple not to test this stuff - especially when it is apparently a problem beyond just me.
I think you should be asking T-Mobile, surely?
iOS 26.1 Kills Cellular Connectivity
