Update: The T-Mobile iPhone crash issue appears to have been fixed. Let us know if everything is back to normal for you, or if you're still experiencing any problems.
If you're encountering random reboots on your T-Mobile iPhone, you're not the only one. Several users on social media are reporting that iPhones on the Uncarrier are flashing blue for a second, and randomly rebooting every 20 to 30 minutes. The issue doesn't appear to be limited to a particular model, with iPhone 5s, iPhone 6 and iPhone 6 Plus owners mentioning that they're facing the same issue on their devices. A particular version of iOS also does not seem to be at fault, with reports of both iOS 8.1 and iOS 8.3 being affected.
According to the discussion on Apple forums, it looks like the issue is caused by the Wi-Fi calling feature T-Mobile rolled out last year. Disabling Wi-Fi calling and VoLTE seem to fix the issue for a few people on the forums.
A Redditer contacted T-Mobile, with the carrier recommending the following solutions:
- Hard restart - hold the power and home buttons down for 10 seconds until the device restarts.
- Clear out your old text messages.
- Do a full factory restore in iTunes, then restore from backup.
The Redditer also wrote, "the sense that I got from the technician is that a) they suspect memory problems, and b) they're getting a lot of calls about it."