Debug mode problem. How to solve it?

I used Debug mode to test my code. it is okay If I set break points and press F10 many many times.

let 's say,

variable q

variable t inside a loop

when q=1 ,t will increase incrementally until q changes and it will start again

when I use debug mode and press F10, t can will increase incrementally without any problem.

q can reach 5 and the program is okay.

But If I don't use debug mode, Just press F5.

Q stuck in 3, and t increases inside a loop forever and never end the loop

I guess a problem in my code? but why debug mode can run my code

[per isakson]

I don't get it. Could you make a small example in executable code?