late development from me, but i've recently learned about a 'stuck keys' problem that seems to be well attested in rm2k. someone (cherry, whose name i've known from rpg circles since the 00's) wrote a utility to reset them, so if you're still interested in playing the game and you're comfortable running .exe files off the internet, this might be your solution: https://cherryshare.at/f/7p0MHz