First, this is a very bad use of a property node. The control itself, or a local variable is what you want to use. A property node for the value is primarily used to communicate between VIs, and not as a substitute for a local variable.
Second, I think that this may be your problem. The alternative certainly fixes it. You may have encountered a bug, or it may be how they work.
Try using a local variable instead. The local variable will allow you to locate the control outside the loop (make it an indicator, and wire a default state to the control) and really makes your program neater.