mmh... I may have to check renpy specific documentation to see if they address the issue
Sadly I dont even have an android device to test
Usually I'm able to just press enter to choose but no matter if I type one letter it just won't let me choose my name.
Mmmh IDK what could be done to fix it, I will have to check renpy doc
You may also try an external Bluetooth keyboard to see if that makes a difference.