Ender 3 V3 KE Layer Problem

I bought Ender 3 V3 KE recently and I already love it. I have never seen such fast and smooth printing. But I have noticed a problem in outer walls, there is always shiny and matte layers and I don’t know why that happens, can someone tell?

Do a PID tuning, there seems to be something wrong with the extrusion, either the temperature is not stable enough or too low maybe.

Hi! What is Pid tune and how to do that? People are saying it’s not available in ender 3v3 ke.

Doesn’t the latest firmware have it in the expert settings? The K1 series has it.

Is there such thing as expert settings? I’ll check out.