Either I'm really bad at games like this (which is totally possible), or the placement of the jam to renew the double-jump in the beginning is just a bit off. I really liked the mechanics though and I think it fits the theme well!
bit late responding but are you double jumping from below into the jam? the hitbox is a lil wonky (completely my fault i ran out of time lmao) so you have to come in from the bottom. hope this helped!