Same issue here until clicked the "Send invitation to all testers" link.The problem is, why the public link only activated after send to all my internal testers?
BillHoo
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
Last seen
User for
Post
Replies
Boosts
Views
Activity
The same issue persists; a reboot of the iPhone can resolve it. However, requiring an iPhone reboot when installing and using Watch-Only apps on the watch creates a very poor user experience. It doesn't make sense to the users. I have posted a more detailed case here: https://developer.apple.com/forums/thread/749431