I'm having a strange thing happen with the text on buttons but I only have a couple of Nexus 7's (original version and current version) and 5's to test on. Every once in a while, when there's ads (AdMob), the text on the buttons in my app turn in to white blocks. The only consistency I've found is that it happens more often if you wait for the ads to appear before clicking on the button (the error happens when you click the buttons). Sometimes it happens when you go out of the game, leaving the task running, then go back to it, but even then it only happens when ads are displaying. I've made a very simple apk to install and try. It's just two frames, with a "Next" button and a "Previous" button to go back and forth between the two. The attachment below has the apk plus a screen grab which shows what the error looks like. Can someone try it out and see if they get the error?