Cellular data stopped working immediately after "upgrading" to 5.1-lollipop OTA (from 5.0.2) on my Nexus-4. I am seeing the exclamation point in the signal strength indicator at all times, except when Wifi is on and connected. Voice calls work fine. Wifi works fine. 2 hours on the phone with Simple Mobile, then 2 hours back and forth with Google support, and still no resolution. So far I have tried:
- Erase and reprogram APN settings
- Remove and reinstall existing SIM card (that was Simple Mobile's suggestion, although I think if voice is working SIM is probably OK. I don't have a spare to try right now.)
- Turning phone off and on
- Reboot in Safe Mode
- Turning Cellular Data switch off and on
- Turning Airplane mode off and on
The exclamation point on the cellular strength icon seems to follow the exclamation point on the Wifi icon, i.e., both go on and off at the same time--when a Wifi connection is made or broken. Is it possible that this may be a bug related to an accidentally shared variable between the two?
Google 2nd level support has said they don't have an answer. They want me to try a new SIM card, which I'm trying to get from Simple Mobile. If that doesn't work they want to "discuss repair options for the phone."
I've seen some other people with similar problems but haven't seen any fixes or workarounds other than what I've already tried. Does anyone have any ideas?