DRV8825 also benefit from TL-smoother.

http://marlinfw.org/docs/gcode/M420.html

Here's the issue: If I jog the X-axis to the right (positive direction) the nozzle is maintaining height as it should, then when I jog back to the left, I notice the Z-axis is getting closer to the bed.

Here's how I came to the conclusion that the Z-axis is moving up less than it is moving down (think Z up .05mm Z down .1mm): I put the x axis toward the center, lowered the nozzle onto a piece of paper until it was too tight to move taking note of where it was free to move (Ex. lower to 0mm feel it getting tight, lower to -0.1mm and can't move paper). Then I would take note of when it would release again, generally taking +0.2mm to release even though I only went -0.1mm.

Here are some lines that might be important...

#define DEFAULT_AXIS_STEPS_PER_UNIT   { 160, 160, 5120, 176 }
#define DEFAULT_MAX_FEEDRATE          { 300, 300, 5, 25 }
#define DEFAULT_MAX_ACCELERATION      { 1000, 1000, 100, 10000 }
#define DEFAULT_ACCELERATION          1000 
#define DEFAULT_RETRACT_ACCELERATION  1000
#define DEFAULT_TRAVEL_ACCELERATION   1000

I'm using DRV2285 Drivers, All tuned to ~0.5V, I've tried tuning the Z to ~1.5V to see if it needed more juice, tuned back down to ~0.5V as it had no effect.

Is this an issue with the DRV8825 missing steps? Or is it something more obscure than that?

I've attached my firmware in case there's anything else you need to know.

P.S. For those wondering about the Z-Probe setup, I'm using an MKS GEN board and have the Z-probe positive lead on the 5V rail, and the Signal wire attached to pin D44 in Aux 2, had to disable some pin-outs for D44 and set the Z_MIN_PROBE_PIN to 44. This is pretty "Dirty but Worky" for now. The Issue I'm having with that is after the Auto Level, if I home then go to 0,0,0 it floats 2mm above where it should be (It's configured so that G28 is safe after Auto-level).