Popups on certain apps suddenly disappear. i use youtubetv alot in a popup window format (meaning its a small window that popups so i can use other apps in the background). normally this seems to work fine, but then at times what happens is that my popup will disappear. when i try and reactivate the popup it wont show up. other common popup apps that work like Maps also dont work at that time. when i try again later, it often works again. any idea why this is happening?