Power_Broker wrote: the problem is that when changing print directions, it pauses ever so slightly (yet still extrudes during the slight pause), causing excess filament at the corners and producing these bumps.
There really has to be something very wrong.
Even with very slow jerk-settings no printer I do know of stops at direction changes that long that
one could really notice a stop especially not with extrusion.
May I ask how long the part in your picture printed?
That must have been hours.....
As wirlybird said before check whether you choose the correct printer in your S3d profile.
Is it a used or a new printer?
Did it ever print as intended?
Maybe a former owner messed with the firmware...