I’ve got two other things to try.
First go to Settings -> Watch Faces -> Ongoing Icons and if that is on turn it off and see if that makes a difference. There is a report of it affecting animations loading and may be something you are seeing.
Second is to change from Sweep to Normal and see if that makes a difference. I see a report of an issue with using the Second Hand as a button in Sweep or Tension mode. It is worth trying this as normal.
If neither of those help Please open a support request and they can give you information on how to create a log and they can then determine what is the issue. Be sure to include all information on the watch you are running on, software version etc.
I will move this to Galaxy Watch Studio forum in case other watch designers have seen issues.
Ron
Samsung Developer Program