What causes these blobby corners
I suspect you are printing through a usb or network connection,  and the communication rate it's to slow for any of many reasons.   A curve consists of many tiny linear movements,  each requiring a command exchange between the PC and printer. 

If you can,  try printing from an sd card plugged into the printer (I'd the printer is so equipped).

This could be worse if the uses a Bowden extruder,  since there is now compression and windup in the filament.