Non-working global shortcut

My laptop has been away for repair. When it came back there was no paperwork - I've no idea what was done to it, but there are a couple of very strange things. Of course, the first thing I did when it came back was update, so it's possible that something there is involved.

1) Not important, but strange - the panel clock was 1 hour wrong. 2) My defined shortcut to launch kpat, my chosen lunchtime relaxation, no longer works. I deleted it and redefined it, but no joy.

The clock business is just a curiosity. Short of messing with the bios setting I can't think why that would be. I'd really like to get the shortcut working again. What could interfere with that?

Anne