This issue still remains unsolved.
I did a test - it seems that the issue is with Garmin Coach-activities.
Watch is synchronized, but only the "warmup" is available on the watch - Navigate to start an activity, select training and navigate down to your calendar and you will get an message to "Download your training calendar from Garmin Connect” (if you only have Garmin-Coach activities on that day).
Update December 19, 2024:
Our engineers are aware of a concern that may effect syncing Coach plans to the watch. If you are experiencing this concern, please feel free to reach out to me via Private Message…
this is exactly the case, 19.41 was beta some days ago, and now pushed to Public Live.
https://forums.garmin.com/beta-program/fenix-7-series/f/announcements/397695/beta-version-19-41---now-available-ota…
yes, a lot of bugs reported regarding the same issue. However, this is still an issue in a non beta-version.
Not familiar with the process of reporting bug for non-beta-versions, but I thought it would be interesting for the community to know that issue is still in the 19.41 version 
this is exactly the case, 19.41 was beta some days ago, and now pushed to Public Live.
https://forums.garmin.com/beta-program/fenix-7-series/f/announcements/397695/beta-version-19-41---now-available-ota-for-all-models
These bugs are not corrected and available to All now 
