Try Changing the width and Hight of the First Layer to smaller Values, no clue Why, but it Fixed this kinda issue before for me!
reducing the width of the first layer seems counter intuitive to me. usually adhession is improved by using widths wider than the nozzle since the plastic has to get smooshiefied into the surface. I don’t know there’s much difference on the first layer 125%-200% of the nozzle width, but I find going over definitely helps. (I use 150% for stronger parts in general.)
or at least that’s been my experience. nozzle height/z offset would be the first thing for me to check, but PLA shouldn’t be warping that bad, IMO, so there might be some thermal issues as well.






Very few printers are going to be able to do 90 degree overhangs even close to nicely. Bridging? Sure. With significant overhangs, it’s always going to wiggle a bit until you get some more layers.
If OP weren’t using this to get as close as possible, I’d say the answer was organic supports coming in from the bed.