This incident has been resolved, and Garmin accounts are syncing correctly again.

We've been made aware of an issue preventing Garmin data from syncing into digi.me libraries. At this time, we believe this was caused by an issue on Garmin's side, and are monitoring the situation closely. We'll provide further information as it becomes available.

You can view Garmin's status page here: https://static.garmin.com/connectstatus/garmin-connect-status-content.html