Does the Roamio Plus/Pro have to be connected via wired Ethernet?

I have a new Plus, and can't get my new Mini to see it via MoCA.

Setup: Coax input to house --> MoCA filter --> Four way splitter.

Off the splitter I have a run to each of the four rooms in the house. One is the cable modem to wireless router. One each to the other three rooms, with one a Roamio and one a Mini. Fourth has nothing.

Had the Roamio for a week and works great. Connects via WiFi. The Mini is in the bedroom and I wanted to connect it via MoCA. Says it can't connect to the MoCA network.

Mini will connect with wired Ethernet, but that is a long cable strung from the router for testing purposes.

So, my question is this. Does the Plus need to be connected via wired versus wireless for it to create the MoCA network?

Thanks,

Jim