Lucky you, for a soak off gel I can't get them off!!!
The tip on the thumb has snapped which would suggest there isn't enough product or you haven't built or placed the apex properly to give enough strength.
It also looks like you have oversized the tips on some fingers. Downsizing tip isn't always a good thing as it will always want to ping back up. Bit if going for a larger size tip taylor to match the sidewalls.
If they have literally just peeled off then it is down to prep.
Give NSI a call, you've paid for and completed your course they will help you out.