MoCA problem in apartment

So I moved into a new apartment (built in 1988). My Premiere XL4 is set up with Comcast that goes through a splitter and shares the jack with my modem and router. I've got a two Minis, one in the Kitchen, and one in the Bedroom. The one in the Kitchen is hooked up with Powerline adapters, and works flawlessly. I tried hooking up the one in the bedroom using MoCA, but it just doesn't work. Temporarily, I stole the kitchen Mini's Powerline adapter, and it works fine. The problem with the MoCA is, there are two jacks in the apartment, and I have no clue where the splitter is, or if there are two separate drops, or something weird. All I do know is that the buildings aren't using a bunch of splitters internally, as there are two cable companies, and they can switch the drops from one tap to the other in the little utility closets on the side of the building. Any ideas for troubleshooting or figuring out how this place is wired, or should I just pay $35 for a used set of Powerline adapters, and get them both on Powerline?