I’ll have to add a note to the game page. I did test the game on chrome/edge/firefox on two different machines. But Godot 4 web exports are unreliable at best right now.
Thanks for letting me know!
I saw you posted your code on github so I took a quick look. I don't know if this is the cause or not, but could it be that the random offsets you're applying to the player position are affecting the jump? Only reason I think it might be related is because the jump does seem to go full height sometimes, so I could see the issue being tied to a random variable.