Sim card issues on screen off

poppyfields

Whenever phone goes to sleep (screen off), on wake up notification icon alerts me that I have no sim card present. Unable to make phone calls or access any data. After leaving phone on for a few minutes this comes back and all works, but as you can imagine - I miss phone calls, etc.
This appears to have happened since the 3rd OTA upgrade. I have tried changing sim card, checked Mobile Networks Settings and even factory reset my phone (   ). None of which solved the problem. Have not found much on googleing, and would appreciate any advice on how to solve this (seems like a software problem).

bencebacsi

Dear poppyfields,

Please, try to process the followings:
1. Remove the SD card from the slot if you have one installed. If your issue disappears, try to use another SD card.
2. To rule out the possibility of an existing software error, I suggest you the flash your phone with SP Flash Tool, choosing the 'Firmware Upgrade' option in the flasher application. That process will completely rewrite the whole software content of your device. - You will lose your user data.
Link: http://community.umidigi.com/thread-3110-1-1.html

Regards,
Bence

poppyfields

Finally sorted. Got a 3rd sim card before the above reply  - and this one worked. Bizzare.