Prusa MK3S weird 'Blobs' on PLA print surface
After hours of trying to fix the problem by trial and error I found that getting the nozzle slightly higher by approximately 0.1&nbsp;mm was the solution. I cleaned the rods from dust, tightened most of the screws again and calibrated the printer. 

I don't encounter this problem anymore even while printing at 150&nbsp;mm/s speeds.