ditto what TheEthyr said Re: your ISP configuration simplifying the MoCA setup … but even greater simplification and optimization is possible if just trying to link one remote room to the router LAN; see the following parallel reply by TomRILReddit from today for another thread attempting the same…
Who’s the provider? Comcast typically will perform this service free-of-charge; that is… grouping and isolating the residence’s coax behind a “PoE” MoCA filter.