Ok here a piece printed by Kessel, layer 0.15, filament pla 1.75, 195°C, the first image is good, the second shows the problem : this during printing was the bottom, and I can’t figure out why layers are so bad, all became good when printing is more vertical. Excuse my English, any idea will be appreciated.
Its the overhang. You need add supports to the print.
It looks like the slight overhang is curling up as it is not fully attached to the offset layer below. Try turning the speed down or using aggressive cooling. This normally works for me but can reduce the overall strength of the print. As mentioned previously, support will work but will leave marks. Depending on how drastic the angle of the overhang is, suppport may be your only option.
Like the others said you have an overhang problem. If you put supports on the model in your slicer then you should be fine.
Many thanks to all