Don’t know if it’s the full picture, but since the latest android patch, my device is not granting “storage” permissions to the game when installed from the PC. But you can go to “App Info” on the device and grant it manually, now my game is saving again. I wonder if it’ll have this issue when installed from the Google Play. hope not.
I though it was 4.21, but it seems is not an issue on UE4 side. but on how Android treats Apps installed from wherever.