Just 2 days back I have updated my Apple Watch S3 on latest update Watch OS 6. After update I have figured out that stand goal doesn't work properly. I observed two things:
1) When I stand at the beginning of an hour, that hour will be more likely to be tracked as idle hour and it won't be tracked
2) When I walk for a minute after few minutes of beginning of an hour say after 20 or 30 minutes then it gets tracked properly and also when I do work out then also it gets tracked properly.
Before watch os 6 it was working perfectly even If I walk around a minute in the beginning of the hour but now its simply not working as expected.
I have tried all possible suggestions like Unpair/Re-Pair the watch, calibrating watch, restart apple watch and Disable/Enable Fitness tracking, but none of the suggested solution worked.