activity not syncing

I’m experiencing a very bad issue with my Garmin Venu 4:

  • my running activity is available on my watch but hasn’t synced to Garmin Connect.

  • during my run, the watch worked fine 

  • I do (!) can open and view the activity on the watch, but it doesn’t appear in Garmin Connect

  • I tried connecting the watch to wifi I I get 44 files not synchronized

  • I also synced the device via Garmin Express, but the activity still doesn’t appear.removed the Venu 4 from the App and re-added.

Could you please help me to solve this problem or advise how I can recover and upload this activity?