Success! 
Thanks for your help tracking this down, it would have never occurred to me that this combination would cause that behaviour.
I’m going to try and get my hands on a tablet to test with as several people have reported this hang (I’m also checking to see if they have the same root cause - at least one of the callstacks is the same as what you posted above).
I’ll reply again once I have more information, and hopefully, a fix 