Dang, sorry, that save erase bug is a bummer. Which save file & hardware were you using? I'll look into it 👀
i play on an unmodded Gameboy Color with the game on a bootleg cart flashed by the JoeyJr from Bennvenn. (I use this cart for long now and its my fist save bug i encounter with. ) Also This is not a dead battery fault bc I played after the incident and i was able to save and load my new save without any problems.