Sky Q screen keeps going to black, and when working you can’t pause it properly, sound continues

[Damon3]

In the last week both the main box and the mini box (Sky Q) have become very temperamental. Pausing doesn't work well, transmission completely fails and then comes back. Tried to call Sky but there's no option to speak to anyone. I've tried the hard reset of the hard drive, didn't work. Thanks very much for any help!