This is the first time I've run into this problem and it seems very confusing. I wanted to print a simple functional part out of PLA and although the first few layers were fine, the 6th/7th layer started to have some weird 'blobs'/deformations on it. I don't know how to fix it and the problem didn't go away after changing the filament. I suppose the problem is related either to my settings or the printer. It is very weird, I fully calibrated the printer right after the first fail.
Settings:
- nozzle 215 °C
- bed 60 °C
- speed 100, 50 mm/s for bridges
- cooling 100 %, but no autocooling in order to print faster
- using PrusaSlicer
Photo: