I have no idea what hardware or firmware version is - I bought it from Amazon today.

So the wifi on this thing works but when I connect an ethernet cable from the deco x55 to a switch that connects to the rest of the house I get nothing, no connection, no notification, no indication that anything is working or has changed.

What do I need to do to connect my wired ethernet devices to Deco x55?

In case it matters, there are quite a few.  I would guess 20.