Strange Ignition Timing With Apexi Power Fc

[ocousins]

Has anyone ever experienced the strange behaviour of huge ignition timing retard on throttle lift?

I am running Apexi Power FC and anytime I lift the throttle to decellerate, the timing retards from (for example) 35 degrees down to 5 degrees, then returns to 35 degrees and gradually decreases normally with the RPM. If I hit the gas immediately following a throttle lift, the ignition timing remain really retarded for a few seconds before correcting itself. I get a really loud backfire pop when I lift. I have checked the ignition map and there is no cell with an ignition timing even close to what it is retarding to. I have seen it go as low as 0 degrees!

Is this likely a hardware issue in the ECU? or perhaps some other ignition component?

I have ruled out the CAS because I checked all the signal lines by back pinning the ECU with an oscilloscope, and they (all 4) are all crystal clear square wave entering the ECU.

On a side note the ECU has other issues such as a really noisy reported RPM even though I am certain the CAS signal is perfect.