I had the same problem as some othrrs; installed the update, didn't get the update features & my notifications quit working. Cleared the gear app cache, hard reset the watch, uninstalled the gear app reinstalled the app & reconnected the watch, nothing worked.
Called Support, they had me go into my phone settings & reset the settings back to the factory settings (not a factory reset). No luck. After that they had me go to a Samsung Experience store & have them try to reinstall the update, no luck.
After 2 days of no notifications as a last resort I wiped the phone's partition cache, restarted the phone, restarted the watch & boom notifications are working correctly again. Hopefully I'm not jinxing myself but after several days, so far so good.
Wish i had the update features, but I'm glad to have my notifications back. Hope this helps.