Ok..this is strange..noting I do like the Roku. I had a ROKU Ultra, in our motorhome. I could NOT get it to connect to our Pepwave modem, which handles both WIRED and Wireless. When you went into settings, to set up connection, the two tabs come up, WIRED or WIRELESS. The new Ultra I got yesterday came in, set it up at home...took it down...The tabs for WIRED DO NOT SHOW UP..It only connects WIRELESS. I bought a new ULTRA so I could get hooked in WIRED. Made no difference, I could not get in, and it always hooked Wirless.........I rebooted it, and made no difference. So I bring the new ULTRA home...hook it up again at home, and the TWO CONNECTION options now appear, Wireless or Wired... At our motorhome, we can not even get the WIRED tab to show. I unhooked the ehternet cable, I rebooted everything..left it unconnected to our Pepwave modem..NOTHING............bring it home, and the WIRE and WIRLESS tabs show at home..................I am lost.............on this one.....fingernails are soar from scratching my head...........ANY IDEAS OUT THERE.....
Do you have anything else connected wired wise to the pepwave modem? My guess is that it's not detecting that wired port from your modem is "live" and therefore not giving you an option to use it that way.
I've seen gaming consoles work very similarly, but in the reverse fashion where if a wired cable is plugged in, it doesn't let you use wireless at all.
Just a thought. I don't know anything specific about the ultra product but do know more on the network/wired/wireless side of things.
My 2020 Ultra will show the Wired option whether or not any cable is connected to the Ethernet port. As far as I can remember all of my Rokus with an Ethernet port always showed the Wired option regardless of whether a cable was connected, but that may have changed with a new model or firmware update. Does any light flash by the Ethernet port when you connect the cable at home or at the motorhome?