I see that you resolved it, but I wanted to add : to my knowledge, delay nodes don’t “pause” the execution. The while continues to loop every frame but stops at the delay since it is still cooling down. When the cool-down of the delay is finished, the remainder of the execution path is executed.
My guess would be that whatever method is used to detect infinite loops picked up that the while was executed many times without the condition changing and wrongfully interpreted that as an infinite loop.
Sorry if you already knew this 
While Anatoliy’s method seems to work well, you could also simply use a Timer by Event and make a custom event “Update Time”. You set it to looping every 0.1 sec. In the event you decrease the time, display it and test if it’s more than 0. If not, you stop the timer using the timer handle and make the platform fall.