Weird
Hi, I have problems with Prusaslicer. Left print is with Cura, right is with Prusaslicer. In Prusaslicer almost everything is on default. Set it to Klipper (I have a non-Prusa CoreXY printer wirh RPi and Klipper), problem also with and without Arachne. Perimeters set to inner one first, 3 walls. What can cause this problem? I would like to use Prusaslicer because it has much nicer finish where it prints flawlessly. Maybe a deafult perimeter setting is bad for my printer?
RE: Weird
Would need to see your Prusa Slicer project file. File>Save Project As to save a PS 3mf file. Then ZIP it up and attach it.
If I had to guess without the project then I would suspect its the way that PS adds solid infill to sloping walls when there is zero need for it. That tends to over heat those areas and you get effects like you have pictured.
If it is that then there are 'ways' around it. Need the project though.
RE: Weird
Thanks for checking it. I see the first few layers are purple but not on the head:
PS project file: renopequenito (1)
RE: Weird
Thank you very much for attaching the project file. I think I have figured out your problem which I couldnt have done without the project 🙂 Its why we ask for them and they are so useful.
If you slice and then look at the preview and change the type to Fan Speed I think you will see an interesting correlation. 
Those layers have the fan turned off. That's not a problem on the legs with their geometry but the body/head is sloping out. Go to your Filament Settings>Cooling and tick Keep Fan Always On. It really should be for all PLA filament profiles. Because those layers take more than 60 seconds the profile is saying that natural cooling is enough, obviously its not.
I'd also suggest changing the min print speed to match that of your slowest print move speed, 15 in your case to match the Small Perimeters Speed.
Give it a go with the tickbox=on.
RE: Weird
That was the problem, thank you very much 🙂 Automatic fan turned off and now works well when I set it to cool parts all the time.