Watch sensor 'burn'?

I have an Series 6 watch bought in 2020. It worked fine till a few weeks ago. I seem to have developed a burn under the sensor on my wrist. I wear the watch for about 8-10 hours a day and only 3 days a week. I looked up this thread https://discussions.apple.com/thread/251463661?login=true&page=4 and it seems to have been a problem earlier too. I stopped wearing the watch and the 'rash/burn' subsided. Wore it again yesterday and the rash/burn is back. Not sure if this is from the recent O/S upgrades that caused the watch to do something that it did not do earlier...any one else who has faced this issue in recent times?