Tried that before, which did not work and was why i put the fuel lines there to make sure it wasnt a crossfeed problem or anything.
As for beam coverage, the thing beaming power lies on the runway, and the beamed power interface tells me it's receiving over half a gigawatt of power, which should be more than sufficient. I think.
Propellant is both in the engine as well as the tank set to Liquid Hydrogen (also can be seen in the screenshot). Unless that does not work in the atmosphere that shouldnt be the problem. I'm pretty sure i also tested others like HydroLox tho, with the same (lack of) effect.
Edit: Alright, i have no idea what's the scientific background or if this is a bug, but it's the Liquid Hydrogen which seems to cause the problem. HydroLOx, Liquid Fuel and Kerosine worked just fine.