What can this be caused by? I have changed stock Anet A8 board (Anet v1.5) to new SKR 1.4 with TMC2209. Then I found out these lines on the walls, i don't know how to determine it. Previously this wasn't so visible, but now it bothers pretty much.
Looks like an over/under extrusion. This can be fixed by:


decreasing/increasing your extrusion multiplier (flow)





lowering your print temperature





checking the diameter of your filament. Do you use the correct diameter?