Hey Oska,
das sollte dir helfen, zumindest hat es bei mir einwandfrei geklappt:
4. Disable uPnP when running multiple nodes
If you attempt to run more than one node on your local network, having uPnP on on both will cause both nodes significant confusion. You will need to use powershell to disable uPnP on all but one.
For version 1.0:
cd %systemdrive%%homepath%\AppData\Local\Chia-Blockchain\app-1.1.3\resources\app.asar.unpacked\daemon\
./chia.exe configure –enable-upnp false
Gruß
Yaku