I learned from some people in this forum a while ago that the auxiliary fan can cause PLA to warp. Since then I have turned off the auxiliary fan in my filament profiles and have had no warping issues. If I have a tall part, I will insert G-code to start the fan at a higher layer.
I was printing something today and when it was getting close to being finished, I noticed that the top surface layers were messed up like there was warping. I couldn’t tell at first but when I took the flashlight out I confirmed that it was warping. I had washed the plate with soap so that wasn’t the issue, I then suspected that I must have forgotten to change the filament profile and left the default one. So I looked at the 3mf file and only one of the four colors I was printing had the fan on, the red color with the fan started on layer 28 and was about 10% of the surface, and it looks like the warping started just after the first layer of the red.
It was a 4 hour print, so long enough to be very annoying. It is printing again with the fan off on all filaments.