That would be crazy if it's that simple.

I read something that if one component is wrong on Flexray, the whole line will shut down. This could be what I'm experiencing.
I should also probably check the OEM harness going between the two ACC sensors. The color codes of the wires are the same (green & pink), so they should match up to the other housing that I connect to, that goes back to the CAN GW.

I also found this thread from an Audi A8, which, only has one sensor, but the wiring is very similar. The A8 here seems to use just CAN and not FlexRay.