Way to end Compare variable loop?

I am trying to make a queue system that everytime you press a button, you wait 4 sec and the solder spawn

but when the variable check is pass it never check again and proceed to spawn 500+ solder

Is there anyway to stop the loop or recheck the variable everytime?

Sorry for my limited knowledge, it just my school project.

It acaully almost work, but if i queue multiple unit it didn't wait until the first unit is finish first before starting another.

Even if it "almost works", that second event on your screenshot runs on every tick, which is wrong. It also has "Wait 4 seconds" in it, which makes the engine to create hundreds of delayed threads. This is a serious mistake, that can cause poor performance and nasty bugs, you should definitely fix it.