The sound is a physical clicking. I wasn't after a fix, even though that would be nice if something is wrong!, it was just to see if yourself or anyone can hear a similar noise during a regen.
I think I've got a video of it somewhere that I was going to show my SEAT service manager, but he wasn't interested...…..
Feel free to share the video. My car is at the garage and won't get it back for a few days so I'll have to check it during the next regen.