Z measurement discrepancy between probe angles – PC-DMIS

I had an issue when trying to calibrate A0B0 followed by A90B90 where the first calibration worked fine, but the second is always aiming about half an inch too high on the calibration sphere.

I measured a 1-2-3 block and measuring both sides with the same angle is perfect, but if I measure the top with A0B0 and the bottom with A90B90, the result is .4044″ off.

I have no clue what is causing this. All probe angles calibrate fine individually, but the relationship between them is off.

Any help would be greatly appreciated!