Hello,
I am not the only person in my playgroup experiencing this issue - I am trying to put RCS engines on a craft for orientation and stability, but am always running into an issue in that the game constantly says that there is no monopropellant getting to the RCS systems. I've configured both the tank (tried both procedural and stock monoprop tanks) and the engines for Hydrazine, but still won't show that they're getting fed.
Here's a Steam screenshot - I've tried putting the RCS ports in different places, and tried a few hypergolic fuels, and nothing works:
http://steamcommunity.com/sharedfiles/filedetails/?id=728219557