FWIW in my case it happened 4years ago on a 520. The ride ended and didn’t appear on Strava but was on TrainingPeaks, Garmin Connect, and other platforms. So I tried manually uploading and got the error with pointer to support article. Before trying to fix, I looked at ride in TP and realized the last 20 minutes of 2 hr ride had jumped ahead by 18 hours. That tool fixed the time stamps of last 20 minutes. 