The Samsung Dev team did come up with that explanation 11 days ago.
This is a problem with the WCS (Watch Core Service), which Google manages. A Google Play Store releases will fix the problem. There are no usual date related to the release scheduled. Hoping you will receive the update in the next two months.”
Are you using the new WFS 1.3.8 Beta? It allows 10 styles with 3 options for each styles I tested it on one of my test watch faces that has a lot of complications and they seemed to load OK. I didn’t try watch hands yet only color styles.