The round must be saved on the watch in order to sync over the score, stat, or shot data recorded prior to the watch shutting off in the middle of the round.
If the watch shuts off and you are not seeing an option to resume the round when going back into the golf activity...then the shot data is lost because the scorecard was not saved.
You can check your scorecards folder by connecting your watch to a home computer and opening the device drive showing in File Explorer/Finder by opening the GARMIN folder > Then selecting the "SCORE or SCORECARD" sub-folder within. If you see a .FIT file showing with a creation date matching the round where your watch shut off...copy the .FIT file to your desktop > Then open the Garmin Express program on your computer and sync your watch after it has been added as a device to then see if the scorecard transfers (if you have confirmed the missing scorecard file is showing within your watch storage.
