Z-axis irregular drift

Hey,
I’ve looked at a few posts with similar issues and talked to support but I’m not having much luck finding a solution. I’m pretty new so hopefully its something I’m just missing.

Machine: Elite Onefinity Foreman

Problem: The Z-axis is drifting irregularly downward while cutting. Does not seem to drift while running a dry run or when running over a previously cut area. Had varied effects of the issue with it dropping about 1/32" over a 4’ span and dropping an 1/16" over 2’. This drift is not being indicated on the Masso.

I just got started and I’m trying to surface by spoiler boards. Initially I was only trying to cut about 1/64" off the top when it first occurred. The GCode was initially set with a feedrate of 70, rpms of 12k,using a 1 1/4" surfacing bit, and no variance in depth after the initial ramp up (Gcode has z-0.0156 all the way down).

Trouble shooting so far:
Checked Collets and retighted.

EMI- Pulled table away from the wall. Vacuum/dust collector completely pulled away with the only connection point being the hose itself, cords are plugged into a separate outlet and breaker. Router (makita) cord pulled out of drag chain and now hangs separate with the only connection point being the mount on on the rail also plugged into a separate outlet and breaker. The Foreman and Masso are the only things plugged into the elite power supply which has its own outlet and breaker. Wires seem to be in good shape from what I can see.

Turned the RPM’s up to 22k.
Slowed feedrate to 35.
Swapped out the stock Z-axis motor for the Z-20 motor/Brake.

Changed out the 1 1/4" surfacing bit with a 1/4" endmill bit,

Ran the same Gcode (except for edits stated above) with every change.

To keep track of the drift we put some tape on the z mount where you can view the coupler with tape on the coupler with a line to show change as it shifts down. While cutting, the coupler would tick intermittently by small increments.