shouldn’t upnp already be active on the SFT1200? I just got my SFT1200 from amazon so I can trouble shoot the device locally with my ps4 and my phone… hopefully I can get it working locally and just implement what I did with my God son’s remotely.
Have you tried tethering from your phone with a usb C to ethernet adapter with a PD charge port? It shows up in the phones tethering section as an ethernet tethering option.