I'm not sure what it is but my phone is android 11 and I've seen some other people also say that renpy is having some problems with android 11 so that must be it.
i think it's because android 11 is blocking access to android files even users can't access it, and that's where game data usualy been saved so if the game needs to writes or read data from android file it's may become like what you described since the game can't access it
