What causes this shading on a matte finish?

Bambu Lab P1 Series Troubleshooting
1

P1S printing matte black PLA, 0.08 layer, default settings. Part of the print looks like the nozzle is wiping up against it causing a discoloration/finish difference during a print. It will always happen in roughly the same location.

bambu-shading-edit
bambu-shading-edit1200×900 433 KB

Any thoughts on what I might be able to change to prevent it?

2

I had this problem before with silk filament, but it was due to the fact that I had used abrasive filament on the normal nozzle, which was causing it to extrude messily then the tip of the nozzle was going back over that messed up extruded area and scratching it.

3

For anyone else with this issue the solution was to slow down the speed of the outer walls.