Solved Waves on first layer

[ppcm]

Printer Model

Voron 2.4R2

Extruder Type

Other

Cooling Type

Afterburner

Hello guys,

I have a Voron 2.4R2 since 2 years, and everything was fine
But since 2 weeks, I have weird waves on the first layer, after that, on other layers, waves disappear and the top layer is smooth
This is particular visible with glossy filament PEI plate

I tryed lot things like, changing the slicer (I am using Orca and SS), the temperature of nozzle and the bed, the Flow ratio, the speed, the belt tension, plate, grease everywhere, ...
Now I am a little bit lost and I don't know where to look for (espacially because it worked well and suddlenly it fails)
Something to know, the pattern of the wave is nearly the same on each print

Here is a picture of the top of the first layer - this face is rough



And here is the bottom of the first layer (the face on the PEI plate) - this face is smooth



Thanks for any kind of help

 

[ppcm]

This morning, the light came on
I made lot of mores tests, and I found the solution.
I don't know why, but the leg of the klicky probe is 0.05mm shorter. Some dust came out???
I modify the switch_offset value, and now it is fine

So if you have suddenly this problem, think to verify this kind of thing...