I have most of the way the Apple Watch works down pat but I am now learning the "little things" unique to the watch. One of them I now have checked off is the AW automatically logging me into my Mac Studio. It worked and than it didn't. All of the needed settings were in place. A chat with Apple got me a script kiddy, no real help there. I googled the issue and I finally found one posting on a Reddit thread with the solution. It is one of those Apple security things that makes sense. This is what is happening every time you restart/shutdown the Mac you have to re-authorize the Apple Watch remote login. If your can remember go into the setting and turn this off before you restart it will save a second restart to re-authorize it.