I am using a watch face (Infograph) that shows the next event on my calendar.
When I change that event on another device, it often takes a long time for the change to show up on my watch face.
For example, I recently changed the next event via my MacBook. The change showed up pretty quickly on my iPhone, but took over an hour to show up on my watch.
All devices are running the latest OS.
Apple Watch
The first (and simplest) thing to try if something isn’t working right is to restart your Apple Watch and its paired iPhone. If necessary (device not responding), try a forced restart. Both methods can be found here:
How to restart your Apple Watch - Apple Support
Restart your iPhone - Apple Support
If that doesn't help, the next steps would be to unpair and pair your watch again and restore from the backup just created. This should result in no loss of data. It deletes all temp and corrupted files and re-indexes the file system.
Unpair and erase your Apple Watch - Apple Support
Set up your Apple Watch - Apple Support
Watch slow to reflect calendar changes
