Can't get pick under the adhesive after constant heating. The crack on my phone is so small that I cant find a single thing with an edge fine enough to get under the phone. The suction cup pops off before I can see enough of a gap (the back is clean, not cracked or scratched). Really struggling to get past step 1. Any suggestions?

Over 2 hours of trying, I keep reheating the pouch and let it sit on the edge for sometimes up to 10 minutes since the directed 1 minute wasn't working. Physically cant get enough leverage on the back of the phone; picks are too thick to get under the crack, and the suction cup pops off before I can get enough force to see any gap open. Phone is 5 years old. I really need some help