This is very strange. I have never actually used an apple pencil really so I can't be of much help, but unpairing and repairing it to your ipad might help. If not you can just forego pressure sensitivity and go for another cheaper 3rd party option, although that might not be feasible as you are an artist.
Yolkbyte
I have heard some people have gotten free replacements after taking it to an apple store, although it was for a different issue regarding a palm rejection problem you could give it a try for your issue