vivoactive 6 software not updating

I own a vivoactive 6 on SW 12.74. 

When the 15.16 update came out, my watch tried to automatically update (downloads the software, installs, resets) but the new software won't apply. I would go back into the watch and it would still say SW 12.74. I tried several times and the update wouldn't apply.

I figured it might be a glitch with the update, but when 15.33 came out, the same would happen and i'd still be on 12.74.

I've tried plugging into Garmin Express, but then the watch would say SW 0.00. It would still work, and when plugged back in Garmin Express, it would be 12.74.

Any suggestions?