Apple Watch WAY over counting flights climbs and exercise minutes

My series 3 has been really over counting the number of flights I'm climbing and how many minutes I'm active. Up until Monday, it was counting these things fine, but yesterday it said I climbed over 100 flights. I almost think it's counting every time I stand up as a flight climbed! It's also counting very normal, non-exercise activity towards my exercise total, things like walking from my desk to to the water cooler, which it never used to do. It doesn't seem to be impacting my move goal, that is, I don't think I'm over estimating how many calories I'm burning.

I've restarted both my watch and my phone, I've checked my personal information to make sure it's accurate, I've checked the location services, all the stuff I've seen recommended on this forum for dealing with this issue. Any ideas welcome!