WIFI CONNECTION

Mine works with the router one floor above.

You don't need the internet or house router to run, only update. Keep it set on the MTH setting. So this could be a non-issue. Just take it up for updating?

I have devices that are strictly set for that. They are not connected to the house wifi.

I don’t connect mine to the internet router. I have a stand alone router I use for all train related equipment.

FYI, I have the Lionel WiFi 2 box and this is what I found with it.  Might be something for you to try to connect your MTH Box to your router.  Recently I had to reconnect my box.  I could not remember how I had done it a few years back.  So starting from scratch, I started My WiFi box up to start the WPS process.  I then went to the Router and depressed the WPS button on the router.  I tried this several times with No Joy.  On a lark, I again started the WiFi box up for WPS but since I was sitting in front of my computer and tired of the ten foot trek to the router, I access the Admin Program within my Asus router and Started the WPS process within the Router.  Connected in Seconds.  Luck of the Draw or was the use of the Admin Program the Answer?  Curious minds will never know as I am not going to disconnect to try to connect again.  Use this information at your leisure (or don't).