Try to force your phone to use a WiFi 2.4 GHz channel. This is what finally fixed my apple watch 3. I have a mesh network so I had to go into the router settings and force 5.0 GHz channel off, you may have a separate 2.4 GHz channel you can join.
My full steps are in a post below.
Good Luck!
deadlamp
Users receive reputation points by contributing quality content to the forums.
Posts include post and replies published on the forums.
Post authors can mark replies as Accepted to indicate successful solutions.
Apple Developer Forums admins can mark replies as Apple Recommended to indicate an approved solution
Post
Replies
Boosts
Views
Activity
Try to force your phone to use a WiFi 2.4 GHz channel. This is what finally fixed my watch. I have a mesh network so I had to go into the router settings and force 5.0 GHz channel off, you may have a separate 2.4 GHz channel you can join.
Good Luck!