Hi Dani
It is a custom Moodle App. It works great in iOS just run an 12.1 update. However on Android we had number of issues. It is really strange that it would work android 8.1.1 but fail on 8.0.0. Even more strange it works perfectly fine on Samsung S9 models operating on 8.0.0 but crashes on Samsung S8 with the same OS. ( I suspect it is maybe related to the npm, ionic, cordova and android studio gradle version compatibility. If you could give me more information on the versions that known to work I will be grateful)
I tired the official Moodle App. It works correctly on those models accept assignment submission feature. In both the official and our custom Apps document upload fails on android with an errors
Please see screens shot below: