A couple of weeks ago, my 2 year old Axon 7 started periodically losing connection to the carrier (T-Mobile). When it does this, I can't make or receive calls or text messages. Carrier data is also not available, but WiFi still works.
When this is happening, in the status bar, there is a symbol that looks like an SIM card with a "?" in it. In the settings, both Data1 and Data2 will be greyed out. Cycling "aipplane" mode does not resolve the problem, but a restart of the phone does.
I am not aware of any trigger for this happening. When it first happened, I restarted and then it happened again within a few hours. Then it went for about a day before doing it again. I cleared the cache and then it didn't happen for several days, but did return. Again, sometimes it will go several days OK, sometimes it will do it again within hours.
Any thoughts? I have considered a factory reset, or doing the Oreo upgrade. I hate to spend the time reloading everything, though, and don't want to loose VR.