No fluid to rear brakes

[MiraclePieCo]

Still trying to get my brake bleeding issue solved - no fluid to the rear brakes.

I have isolated the lack of fluid to the rear brakes as the combination valve. When I disconnect the lines and pump the pedal there is good flow from the front port but barely a trickle from the rear. I have double checked with air: when I blow through the front brake ports (yum, brake fluid tastes good) there is plenty of flow, but through the rear port almost no air goes through. Please note that it IS NOT THE DIFFERENTIAL VALVE. I am using the little brake bleeding tool, and I have checked that the valve is centered and not triggered. Even disassembled it, manually centered it and marked it with felt pen to visually verify. So what's the problem - did they mistakenly send me a disc/disc valve? Or is this the way it's supposed to be? If so, how do I bleed the system when I can't even get fluid to go through the lines?