This is because it is based on umidigi firmware and they do not provide any major update for their devices.The custom Rom Eragon stayed unfortunately at version 1.0 for a long time now. Are there any other and newer custom roms which works as good as Eragon? A change of the rom should not lead to errors and not working features. Does anyone have a recommendation?
You can use any ARM64 A/B GSI but charging when phone is turned off do not work, also many users reported lower signal strength...