That sucks, but hey, at least you get compensated for it. I think in some states they even have to pay you for a certain amount of time at minimum even if you only work for 10 minutes.
It happens very rarely. The times it does they do it under the guise of me being potentially fired if I answer wrong. Ie they want immediate clarification of what I did in some crisis but really just want info. Not paid and I'm actively searching for work.