so I've had similar problems in Speed It Up!, and the author found a solution https://itch.io/post/685688 that might work for you as well :)
Hey, I took a look at the fix for that game, and unfortunately we're using different methods for jumping. Speed it Up! appears to be controlling the player manually, while I'm applying a force to the player physics object to jump. I don't see a way to apply this fix to my game.
Sorry that you can't play my game, and I hope that you've enjoyed the jam.