Blobbing at corners or any place with a sudden change in direction (i.e. where motors need to stop or start on a dime) often causes this kind of (inconsistent) blobbing. The reason for this is that pressure builds up in the extruder, while this is fine when the print head is moving and it needs to keep extruding, when it suddenly stops for a moment (like at a corner) that pressure causes some extra filament to ooze out.

A couple of possible fixes. Try 'pressure advance' or a similar setting some firmwares/slicers have to combat this sort of thing. Secondly, try upping your jerk in firmware, this lets the printer get moving faster and shortens the time spent stopped at the corner so less filament oozes out and creates the blob. Upping jerk can have a negative impact on print quality with regards to ringing and skipped steps though so it's a trade off.

That being said, I can't see the thumbnail so I'm guessing based off the 'blobbing at corners' description.