Corrupt .fit file - running activity that seems locked (\fenix 7S\Internal Storage\GARMIN\TempFIT)

Yes, 13 kb is too small. You're sure there is nothing in the \fenix 7S\Internal Storage\GARMIN\Activity folder with the same date?

Have you tried a manual upload from your Garmin device to Garmin Connect Web - How Do I Manually Upload an Activity I Recorded to Garmin Connect?

If you get any message other than Import Complete, then there is a problem with the file. Attach it to this thread. We can take a look to see if it is repairable.

• Zip the file, then in a reply post Insert >> Image/video/file >> click Upload >> browse for file >> OK.
• Or upload the fit file to a reputable file sharing service, such as OneDrive, Google Drive, Dropbox, make the file public, then paste a link to the file in your post.