Missing Activity, Won't Sync to Express, No Files in Folders

As title says, I have an activity from 7/21 that is saved on an Enduro 3 (latest Beta), but won't appear on Connect, Strava, etc. Tried uninstalling, re-sync'ing via BT and WIFI, etc. Activities before and after sync'd fine.

Using Express (and cleaning contacts, two cables, two computers, uninstalling, reinstalling, running as admin, etc), the watch won't connect, but shows up in Windows 11 File Explorer. However, the Folders in the watch are all empty. Watch memory is at 43% capacity.

Any ideas out there? Thanks much for your time.

Dave