Screen keep switching back

Possibly of interest:
https://www.chess.com/blog/VladimirHerceg91/using-en-passant-to-gain-a-mental-advantage
It's nothing to do with en-passent moves, it happens on all move with all pieces.
And as I said it seems to happen on all options like "chat" and "analyse"

Maybe this wont help because you've already done it, but basic maintenance would be to make sure your browser is the latest version, clear your cache and cookies, and reboot. That solves more problems than you might think. You may also want to try a different browser to compare issues.
Hi,
I have a small problem with my setup.
Firstly, when I try and make a move the piece immediately returns to it's original position. Sometimes I have to make the move again and again with the same result, but when the "tick" button lights, and I click it, the piece then makes the move.
Likewise when I click the "Chat" icon, the screen shows the chat entry screen then immediately returns to the moves list screen.
I also like to use the analysis button to explore possibilities, but when I click the "Analysis" icon the screen immediately returned to the moves list.
Although I haven't tried it, I think this happens with all options.
I must have something wrong in my local setup as no one else seems to be reporting this problem. What am I doing wrong.
Regards, David.