Realising I was standing directly under the only light source in the room, I turned this off and instead switched a lamp on, pointing it at the wall rather than into the room, and it was fine once I'd done that. Also noticed this morning someone reporting that changing the light colour (if you have the option) sorted problems out. Just in case this might help anyone.
I've never had to mess with lighting in this room but now it is Xmas there are different lights on, some quite bright RGB stuff. Hmm.. thanks for the tip! Back in the early days of Vive I nearly gave up after a week of poor tracking until I learnt that a large mirror in this room was the interference culprit. I wonder how many people suffer from issues like that and not realising. Hopefully monitor screens are not reflective enough to cause issues as mine is 38"
