Why while loop doesn't broken with break code in if check? +1

I made automated throttle controll vizzy program for my new rocket. It works while vehicle's Stage is 1, and stop working when S1 separated. But some reason, it work over S1 separated. I added 'if Stage = 2' code in while loop and 'Brake' code in it, but it doesn't work.

2) Reentry fin activate and heading setting code in S1 chip working not in S1, in S2.