(This article has been updated to reflect a statement from T-Mobile. The update can be found at the bottom of the page.)
If you have updated to iOS 10 on your U.S. T-Mobile/MetroPCS or Australian Telstra iPhone, you may have received a prompt to update your carrier settings soon after the upgrade. Reports indicate doing so could cause issues with the operation of the device.
MacRumors reports some T-Mobile and MetroPCS customers report that once their iPhone loses service temporarily, the device is unable to re-establish a cellular connection unless it is fully restarted or network settings are reset. The issue began showing up after the latest 25.1 carrier update on iPhones running iOS 10.
Reddit user Hitokill:
I am in the same boat as many others. If I can stay connected to the LTE network the 25.1 update is fine. However, I work in a building with certain areas that have no coverage. Once I walk in those areas and lose signal, then walk to an area where I normally have full bars I can’t get it back on no matter what I do (hard reset, Airplane Mode, etc…) The only fix I found was going into settings and Reset Network Settings. Totally sucks but that is basically what I have to do. T-Mobile rep said he did something on his end too, but didn’t fix the issue when it came back.
In related news, several Telstra customers in Australia report Visual Voicemail stops working after an update to iOS 10, and applying the new carrier update. One users claims they get no indication that they have new voicemail, and that nothing shows up on the voicemail screen, even though voicemails are definitely available for the user.
At this point in time, it isn’t clear if Apple is aware of the issues, but we’re sure reports such as this will prompt them to work with T-Mobile and Telstra to fix the issue. We’ll keep you updated on the situation.
UPDATE – 1:00PM CST: T-Mobile is warning iPhone customers not to update to iOS 10, after several reports from customers about “connectivity issues” caused by the update. The issue appears to be affecting iPhone 6, iPhone 6 Plus, and iPhone SE customers, although it’s possible it could also affect the iPhone 6s and iPhone 6s Plus as well.
The carrier says it is working with Apple on a fix, and says an update should be available “within 24-48 hrs.”
If you have taken iOS10 on those iPhones, you can temporarily fix by powering down & back up. Permanent update coming within 24-48 hrs.
— T-Mobile? (@TMobile) September 15, 2016