Same issues here. What (somewhat) worked for me was to enable the personal hotspot on the iPhone that the Watch is connected to. Then connect the Mac and the Watch to that hotspot. Do not connect the iPhone via USB to the Mac. Restart Xcode and maybe have a look into "Window > Devices and Simulators". However, copying shared cache symbols from the Watch literally takes forever and is usually stuck at 0% or 1%. This is definitely NOT the developer experience you would expect from Apple.