Possible probe issues / what is the XYZ in the probe geometry?

[[Be...]]

We are measuring a part that has several holes going around the perimeter and for two holes on the bottom have to switch to an L-probe.  Really its a star probe that we only put one leg on.  And it works ... until it doesn't.  So it works for a week or a month then it stops working.  We don't have a reason why.  So I get introduced to the problem and my first thought is that the parts are actually bad.  We verified with two separate independent machines that the part is good.  The part is measuring oot in the +Y direction on just the one machine.

So I inspect the program and it seems fine.  No changes.  It is still running fine on other machines and comparing the programs they match.

So I am thinking maybe it is the probe or probe calibration.  They build a new probe from a working set.  Same problem.  We delete the probe and recreate it.  Same problem.

So I start looking closer at the calibration and I guess I don't know what I am looking at.  Forgive me that the probe numbering does not follow convention.  For whatever reason, they made probes 2 and 3 and those are the only orientations that are actually used.  I made the rest of them just to have more data.  Probes 1,2, and 4 are done on one reference sphere location.  Probes 3, 5, and 6 are made on the other.  

So, what does the X, Y, and Z mean? The main stem is maybe 3 inches long and the probe sticks out to the side maybe 1 inch.  So when A = B = 0 the main stem sticks straight down and the probe sticks out to the left in the -X direction.  When A= -90, B = 0, the main stem sticks straight down and the probe sticks out in the -Y direction.  I haven't been able to think of anything that makes sense of the XYZ for any two probe orientations.