problems in the initial layers

[Luke]

Good morning all
I have a Longer lk5 pro and for a few weeks I have been experiencing some printing defects: the first layers develop malformations only on some edges of the print, that I can not fix by changing the temperature,cleaning the nozzle, changing the speed or adjusting the leveling of the bed. I also tried to change the filament with a new one, the result is the same.
Once the first layers have been printed the next layers are perfect. I attach photos:

[Luke]

[LePaul]

Have you gone to the Teaching Tech Calibration site to dial in the esteps and the slicer flow settings?

https://teachingtechyt.github.io/calibration.html

At first glance it looks to me like you are over extruding a bit

[Luke]

Thanks for the suggestion, I'll try to follow the guide you linked to me.
In any case, if it is an overextrusion problem, shouldn't it occur on all layers?

[LePaul]

That's a good point It could also be that the better layers are when the fan is on
I always start with temp towers, flow rate and retraction tests for my materials