I have exactly the same problem. How did you fix this issue? Does anyone have a solution for this?
Edit: I just noticed, like in the original post my remote client shows my local IP (192.168.1.xxx) instead of my external IP like for all other connected devices. What could be the reason for that?
Edit 2: If I generate a new ID and just link a folder everything works as expected, so I think my setup is correct. But the linking of devices of the same identity does still not work.