Hi there,
recently I implemented chartboost interstitials and a more games button. On the simulator everything seems fine, also on ios I haven’t noticed any problems (using the gremlin plugin there).
But on Android devices I have following problem:
Sometimes (perhaps in 10%) the gray background underlay beneath the interstitial ad doesn’t go away when closing the ad. There is no way to get back to the game then. I have to shutdown the app and restart it. Can’t really reproduce it, it just sometimes happens randomly, but when it happens it really sucks 
Do you have any ideas how to resolve that issue?
Regards,
Jo