I've got a Xiaomi Mi 10 Ultra with the latest Android 12 and I think there might be a bug with A-GPS.
When I'm in an area with zero data reception I will frequently lose GPS lock.
I can then toggle GPS off and on in Googlemaps and a new GPS lock is instantly made, but the lock disappears again after 5 minutes.
This loss of GPS lock continues to happen:
In both the Chinese and EU ROMs.
When Google Location Accuracy is on or off.
When airplane mode is on or off.
When Mobile Data is on or off.
When I'm in an area with voice reception but no data reception.
Strangely, when I physically remove both / all SIM cards the GPS lock is maintained with no problem.
The OS GUI does not allow me to disable both SIM cards at the same time so I have to physically remove both of them if I want to run on zero SIM cards and maintain a GPS lock when there is no data reception.
So it appears that there might be a problem with A-GPS? Without data reception A-GPS doesn't work and it seems like it isn't falling back on the satellites themselves, and is instead just dropping any kind of GPS lock?
Any ideas of ways to get around this? Perhaps there is an Android command I can run to actually disable both SIM cards without having to physically remove them?
Or a command to disable A-GPS altogether and force location lock using only satellites?