Welcome to game jams! A game design tip: give players some leeway when they walk off platforms, as in still allow them to jump even though they've left the platform. Even a 0.3s leeway is good enough~
Yeah, I even tied spamming the jump button XD. It somehow didn't trigger. Leeway implementation: something like if player not on floor, run a timer. if timer has time left (not 0), jump_able = true. something like that roughly.