Top and bottom layer problem  

Top and bottom layer problem

Hello,

I'm trying to find a cause of this weird behavior that started to appear recently on my prints from MK2:

The stripes on the surface are also quite rough on touch with little pieces of filament sticking out.

I'm using default settings in PrusaSlicer (v2.1.1), Prusament PLA with Prusament PLA preset, printer is not modded at all. I've tried checking:

• Unloaded the filament, it has no marks of grinding. It only has an imprint of the gears in very consistent and rhythmic manner.
• I've never used anything else than PLA, but I suspect it might be the nozzle that might need replacing / thorough cleaning.
• Pushed the needle through the nozzle to clean it up, after loading the filament it was flowing out in a straight line, however I got a bit of uneven thickness:

But I guess that's normal. Second load (after answering "No" to question about clear color, it got much more consistent:)

Any ideas on what could be wrong?