I have issue on 5.5. it doesn’t work. Did you test it on 5.3 or lover versions?
Edit:
Just tested on 5.4.2. When I make bluprint with static mesh and then use on click event (of static mesh) it doesnt work, when I switch to hit event it works like charm. On the other hand in 5.5.0 and new one 5.5.3 it have same problem plus it is not possible to switch material even if you use hit event for pop up widget.
It is not be updated for 5 years is there a place to send mail or something about this?