Thanks for the diagram. Unfortunately, it doesn't clear-up the most important question...
How does the Mini's coax line connect back to the coax line connecting to your MoCA-creating Roamio Pro?
See attached:
Though I'm wondering if the name of your diagram,
'Apartment Network.jpg,' doesn't hint at the underlying issue... that you live in a "multi-dwelling" building, and so your rooms may not be isolated from the rest of the apartment building/complex. For reference, you may want to take a look at this PDF from Cisco...
... specifically, pages 17 & 18 that discuss multi-dwelling buildings. See attached:
The "solution" on page 18 demonstrates how an apartment/condo *should* be wired, assuming a MoCA-compatible splitter is used, while page 17 may depict how it currently *is* wired -- noting that the splitter in the page 17 diagram may also be a MoCA-hostile splitter or amplifier, further complicating connectivity.