I used video chat at 15:30 and the image didn't flip. Switched off the device and made another video call later that day at 16:30 and the image flipped.

Just for the record, I had no such issues prior to Diablo so I am sorry that I can't help anyone.

Re the removing and replacing battery fix, I do that every day (my batteries are charged externally) so that had no effect on my experience.