I dont normally do this to posters, but ...use search! There were 3 threads about this on the same page of the forums.....
Your answer... it's not a glitch, it's a piece of software, any software, using acessibitly services in a way that it was not designed to be used. So turning off any software listed in that same area as keeper, will fix it. You could alalso use one of the 1,000,000's of other calculator apps in the play store. In my case greenify causes it. I would expect to see google close the exploited accessibility hole, rather than fix the calculator.