JL Audio HD-RLC not working on both amps

I recently added another amp and sub to my set up. I also have a HD-RLC that was working perfectly with my 700/5 and one sub. I put the other sub/amp in and with the correct splitter (Radio Shack part 279-008, as suggested by JL) it only attenuates one of the subs. I have tried two different splitters, three different phone cords, and have swapped them out every way possible. I guess this means I probably have a bad HD-RLC? I contacted JL and they are actually stumped on this issue as well. He even built my set up at his location and tried it with all the same parts. He said it worked just fine for him. Anyone else had this problem with one of the knobs? I guess if it won't work I will just buy another knob and use two of them. It sucks to do it that way but I can't stand having to dig through the head unit menu to take the bass out of the music when I have had enough of it.

Also, my set up and connections were verified to be correct by the JL rep so it is nothing I did.

 

The shack sells two types of phone splitters. One that sends equal signal out to two jacks, and one that splits "line 1" and "line 2". Easy way to tell the difference is the one you want has 4 wire connectors in both outputs.

 

Yup. I bought the part number JL suggested. It is part # 279-008. I've tried two different units. No luck. I also checked to make sure I was using a 4 wire cord. Even the technical support people are baffled by it. Still no luck. It's frustrating.