Same here guys, now I'm feeling less lonely and it's seems like it's a wider issue.
It's probable Google disabled the possibility for newcomers to add Google Assistant as the default one because of battery drain.
Hi all,does anyone has this issue with google assistant not working on the watch? I can install it but when I am trying to set it up (via the phone), it just opened my google news feed and nothing else is happening. (the same as when you swipe your phone to the right from home screen). I've rebooted my phone and factory reset my watch. Same things keeps happening. Thanks
Same issue... originally setup just fine on Galaxy Watch 5. Then I had issues with the Timer app causing me to reset the watch. Now when attempting to complete setup, I get a spinning white box. Extremely frustrating! It's still within the return window. I'm about done with it.
BTW.. I have it setup on previous watch (Watch 4 Classic) and still working fine.
I found this on Reddit: https://www.reddit.com/r/GalaxyWatch/comments/x4eqyr/i_cant_activate_google_assistant/
I've followed the steps from slagg3r to remove myself from the Search Beta and retried setting up my watch. It WORKED flawlessly. Give it a shot.. good luck!