pocketing start point changes on its own

[kendo]

Starting two weeks ago...
I used a helical entry with a 3/8 endmill into a pocket that measures .65" in X by 1.00" in Y.
I cut it from the center out by setting a bit parameter in the TPC.
The start point picked by mazatrol was going to over-cut the wall so I had to manually change it or the control would alarm out. Only the Y value of the start point had to be changed since the X started in the center of the pocket. The 3/8 endmill was comped to an ACT diameter of .374, the job ran fine and finished with no problem.

Fast forward to this morning...
Same job, same program, new endmill set to ACT diameter of .375, The tool over-cuts the wall of two of these pockets and scraps the 1st part......!!!!!?????? When I changed the ACT diameter back to .374 it uses the good start point and doesn't over-cut the wall...!!?? This repeats over and over to the amazement of everyone else in the department.

The X value of the start point is the only thing changing and its colored yellow showing that mazatrol had picked it. (the value shown in the program doesn't change, but the tool path shows that its going to over-cut the wall) The Y value stays constant and is colored white to show that it had been manually entered. When I manually entered the correct X value, the only difference was it turned from yellow to white, but this problem went away completely.

Why would this happen?
Will this problem repeat on every VCN 510C mill w/ matrix control?
Why didn't the control alarm out when it picked a new start point that was going to over-cut the wall and ruin the part?

[kendo]

these images help tell the story, this problem IS repeating on both our VCNs