I had a strange issue where Cura wouldn't load (hung at loading profile). Third try it loaded. But then my petg print kept extruding fine on the part and first two lines of brim, but all brim lines after the first two were under extruded by about 50%. Part kept warping up since brim was not well attached. I was printing fine the day before. I tried all kinds of levelling etc but it just wasn't working. Then I remembered the cura hang at loading profiles. I uninstalled cura, reinstalled, then typed my settings back in and it started printing fine. All brim lines extruded correctly (no levelling between reinstalling cura). I wish I saved the gcode output to compare... I kept saving to sd card and wiping.