My TP-Link AC1750 always responds with a 500 error to UPnP requests unless the NewRemoteHost field is included. It doesn't actually seem to be used, but just has to exist (or I guess an empty value is actually a wildcard according to https://upnp.org/specs/gw/UPnP-gw-WANIPConnection-v1-Service.pdf).
My TP-Link AC1750 always responds with a 500 error to UPnP requests unless the
NewRemoteHostfield is included. It doesn't actually seem to be used, but just has to exist (or I guess an empty value is actually a wildcard according to https://upnp.org/specs/gw/UPnP-gw-WANIPConnection-v1-Service.pdf).