Try turning the camera into 720p mode instead of 1080. The Epic and Scarlet output full 1080 at 23.98 fps progressive. Very few other cameras output their signal over HDSDI as full progressive - most, especially older cameras, output their signal as PsF, which means its outputting an interlaced signal where the two interlaced segments are each half of a progressive frame. Your monitor may have been designed with PsF in mind, but in 720, signals have always been progressive, so the monitor shouldn't be thrown off by the progressive signal coming out of the Epic.
I've had Epics burn out my 3G SDI board on my Marshall. I talked to another op who had the same problem twice. I don't know what the problem is with Epics and some monitors, but I hope that someone figures it out, and comes up with a solution.