When I switch between other apps back to Pik on the media box I get a "stuck screen" response via the following flow.
Home page----Netflix/Plex----play a video----"hit" Menu Key-----spinning wheel or black/grey screen.
I can recreate this experience about 70-80% of the time.
Spinning wheel fix: To "fix" this issue I can hit guide and than select another channel.
Black/Grey Screen: Usually have to close the Pik app and re-open. (this part is annoying)