Curved Perimeters are Skewed  

Curved Perimeters are Skewed

Sorry for the kind of vague subject. I'm really not sure how to describe the problems I'm seeing. Mk3 Kit. Not my first printer - also have a MakerGear M2 that I assembled as a kit a good 5 or so years ago - but this is my first Prusa. It passed the Self Test indicating X and Y are perpendicular. The Z calibration went great. Dialed it in and got an awesome first layer with a setting of -0.685 mm. Moved on to print something from the SD card - the Prusa logo. It seemed fine at first. Then when it got to the letters, something seemed... off. It's like it wasn't completely filling in the solid area, and the letters themselves seemed skewed. I decided to slice something; trying to rule out bad gcode files on the SD card. I sliced a Benchy in Prusa Control using the default of .15 mm layer height and 20% infill. At first it *seemed* ok, but I noticed some nasty zits and blobs on the bow. Then after it finished, a glaring issue surfaced. The stack - which should be a cylinder - is a strange, skewed, pointed oval.

I didn't observe any skipping in the belts on X or Y. Square shapes seem fine. It's butchering anything curved though. More specifically, it's really messing up any curved perimeters. Looking back at the Prusa logo, the infill for the letters looks correct. I mean the quality of the infill isn't very good at all (very blobby), but at least the *shape* of the infill looks ok. The perimeters are all way off though. Really not sure how to diagnose this one. Any ideas?