If you wait long enough you will get this error, but you can't respond to that request. If it shows, after you restart your watch and enter your code, it still doesn't connect. If you don't restart, then you will never get prompted. 

At least you can see it! I'm starting to think they are discouraging Apple Watch App development at this point.

Some progress. Either waiting a couple of minutes or using the cable for the phone got it to show on Xcode. Hopefully the Transport Error thing will pass now.

I'm just doing straight up Xcode with automatically managed signing. I'm getting upgrade errors because the team ID that Xcode has is different from the one showing on the developer portal. The one on the device is right, but the one Xcode is using has the wrong team member ID, so I'm confused.

Team ID is WFNDASXC9R Xcode keeps using WW2V9Q82B8 What sticks in my mind is that when I started using Apple to host my email domain, I changed the email address somehow with my developer account? It's just that the ID seems the same since these apps have been untouched since long before that. It's funny how the really strange problems end up with you! Thanks!

That development one for me is A9U365295Y. There was a distribution certificate in there with WFNDASXC9R in the common name. I revoked it on Monday to see if that would help as well as clear out all the expired ones. Today I totally removed it, downloaded the old version to the phone and tried again. Same error with the same values. Is there any way to get the identifiers in sync, or is automatic signing forever broken for all my apps now?

I removed and revoked the signing certificate that was there and had Xcode make new ones (after rereading the docs again). Now I was able to run from Xcode and get it installed. Guess I over think things. As always, thanks for the help!

That led to an App Store Connect warning stating the opposite. App Store Connect Warning Potential Loss of Keychain Access. The previous version of software has an application-identifier value of ['WW2V9Q82B8.com.macplugins.rot13.rot13-intent'] and the new version of software being submitted has an application-identifier of ['WFNDASXC9R.com.macplugins.rot13.rot13-intent']. This will result in a loss of keychain access.