Yeah don't even bother with filing feedback there. We have reported Feedback numerous times for connectivity issues between Xcode and Apple Watch as well as connectivity bugs in WatchConnectivity between iPhone and Apple Watch. Literally nothing ever came out of that. You can also check StackOverflow for issues on this, it's been going on for 10 years at this point. They simply do not want you to make Apple Watch apps that's all. What you can do is what we have all been doing for years: Keep restarting your Mac, your iPhone and your Apple Watch in random order until it finally works for a while. Sometimes even resetting your Watch is required.