Using 3.3.3 stable I have the iOS export dying when the html5, Android, and Windows exports all work.
A while ago I had a similar issue with the Android build where
var line := get_node("Control" + str(i))
line.visible = true # this line dies only in Android
Fortunately it was code I could just comment that out, but it really appeared like the Android export was mis-compiling and I am worried that the iOS has a similar issue somewhere else.
I am slowly trying to track down where, but I am curious if anyone has seen something like this before.