Regularly spaced lines on pieces (Z banding?)

[granite meadow]

Setup: VCore 3.1 300, LGX Lite, Rapido, Orca Slicer, RatOS v 2.0.1
These prints were made with Polymaker CosPLA at 200C

Hi everyone, I'm currently experimenting a bit after noticing my prints have this really annoying uneven surface, showing these equally spaced lines (that seem to have 4mm spacing, so it should be Z wobble?)

It seems like setting the wall order as inner/outer/inner mitigates the issue, but it doesn't solve it at all (all photos are from pieces made with the standard inner/outer order just saying)

I already checked my Z rods and they are straight, PA and IS are calibrated, PID tuning of bed and extruder was made.

What else should I look for, given that it's probably Z axis related?

[junior sundial]

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[primal plover]

I had a similar issue some time ago and it was due to the slicer. Is it set for "inner/Outer" on the wall printing order? That's what caused it for me (orcaslicer).

[granite meadow]

yes, in that case (as seen in the pics) it was set to inner/outer but switching to inner/outer/inner only seems to mitigate it, it doesn’t solve it completely

[desert pilot]

I've that too, replaced orbiter 2 with 2.5, linear rails with Hiwin ones, and printed arms with MandalaRose's machined arms, but still there.