X-Axis Not Behaving as Desired

I’ve finally gotten my CNC mill up and running (again), but I seem to be having an issue with TinyG arbitrarily adding movement in the x-axis. If I didn’t know any better I would say it was backlash, but the measured backlash is minimal (~0.0005in).

I designed up and posted a simple operation to create 4 triangular thru-pockets within a rectangle in fusion. The diagonals should be uniform in thickness. When the operation is complete, the result is not as designed, but only seems to affect the x-axis. On the two vertical cuts, for instance, it appears to be cut on the diagonal relative to the previously cut edge. If it were a tramming issue, both the previously cut edge and this vertical would still be parallel. The measured difference is 0.5mm.

There’s other issues with the operation, but all seem to be related back to this x-axis issue. I’m thinking there might be some bad-mojo occuring between the G code provided by fusion in some of the operations (namely 2D contour and adaptive operations).

The following options are what is set in the fusion post dialogue:

(Built-in) Allow helical moves     No
(Built-in) High feedrate mapping     Preserve Rapid Movement
(Built-in) High feedrate     0
(Built-in) Maximum circular radius     1000
(Built-in) Minimum chord length     0.25
(Built-in) Minimum circular radius    0.01
(Built-in) Tolerance     0.002
Optional stop    Yes
Preload tool     No
Separate words with space     Yes
Sequence number increment     5
Start sequence number     10
Use sequence numbers     No
Use active spindle     Yes
Use G28     No
Use M6     No
Radius arcs     No
Write machine      Yes
Write tool list     Yes

What is needed from me to help me troubleshoot this issue?