Apple Watch 6 is recording standing minutes incorrectly

Last two weeks my Apple Watch has been claiming that I'm standing all the time when the watch is on my wrist. When it's in the charger, there are no standing minutes for that time. So that makes average of 1222 minutes and 23 hours per day. The issue started after an update, and the new update (watchOS 9.1) didn't fix the issue. Haven't tried yet to reset the watch to the factory settings, if there is something else I could try first. Otherwise the training and health app seems to be functioning correctly, steps for example seem reasonable.