Z-upgrade - new problem

I have had an X-carve since 2019. It has worked well in my classroom. I recently upgraded it with the whole kit. New Z and 9mm belts.
I have trammed and squared it, and made sure the GRBL settings are correct. I have adjusted the dip-switches and verified that they are correct, and verified that it will move the right distance in the z. The most recent firmware is installed, and I have the Machine set up in easel as explained and expected.
I home it. And probe it before the cut. I have made sure my probe is the correct heght as measured.

My problem is that when the depth of z cuts, it will not go to the complete depth, and then all of the next cut starts higher, and goes less deep. The cuts after the first all cut air for basically a few passes before enteringthe material. I have tried many times with differn’t programs and looked over the g-code.

  • A .75" cut is only 0.537" deep for example. (71%) Cut to be all the way through with tabs.
  • A 50. is 0.3275 (65%)
  • A 1/4’ cut is 0.075 (30%)
    And the 1/8 cut never cut. They start too high above the materil

The x and y cuts are also of a bit. They cut constantly up to a 1/32 short

Has anyone else had this problem?
It’s hard to teach tolerances and fits with the machine off this way.

Board pic.

Simple cuts, but none are deep enough.

I am going to guess that you have the Z assembly mounted too high and cannot reach the depth you desired.

I wish that were the case. I can get down to the waste board. Thank you.

FYI, I switched to another computer and I am cutting correctly again. It’s bizarre, since the same drivers are installed. Interesting anomaly.