I’m not getting notifications when I close my rings

On your iPhone tap:

Watch > My Watch > Notifications > Activity

and make sure 'Goal Completions' is enabled.

If it is, the first (and simplest) thing to try if something isn’t working right is to restart your Apple Watch and its paired iPhone. If necessary (device not responding), try a forced restart. Both methods can be found here:

How to restart your Apple Watch - Apple Support

Restart your iPhone - Apple Support

If that doesn't help, the next steps would be to unpair and pair your watch again and restore from the backup just created. This should result in no loss of data. It deletes all temp and corrupted files and re-indexes the file system.

Unpair and erase your Apple Watch - Apple Support

Set up your Apple Watch - Apple Support

Same issue I'm having on my S3 ever since updating to watchOS 8. On some days I get the notifications when I close my rings, on other days I don't. Whats weird about this bug is that I get all other notifications with no issues, including my daily longest move streak. The only notifications giving me issues are my goal completion ones. All settings are turned on for those and even tried un-paring and then re-pairing but that only fixed it for a day or 2 and then they started being unreliable again.