ABS de-layering on Ender 3
Welcome Fox_89 to the SE 3D Printing site.  Thank you for bringing your question, and I hope you contribute both questions and answers in the years ahead.

I understand that you've tried everything, so I have nothing new to suggest.

Never the less, I would suggest some possibilities, perhaps one of which you haven't yet tried:


Extrude hotter filament.  Increase the nozzle temperature.  My
printer (Pruse3D i3m3s) prints ABS at 255 degrees C.  Give the layers
a better chance to melt together.
Print slower, so that the layers have a longer time to melt together,
and they have a longer time to cool before the next layer reheats
them.
Use a cooling fan to bring the part to equilibrium more quickly.
Try a different filament.  Not all filaments have the same shrinkage.
Hatchbox has worked pretty well for me, but try another manufacturer.
Try another color, like transparent.  White can be a difficult color
because it must carry a high pigment load.  Black can carry less
pigment, and might be easier to print.  "Transparent" or "natural"
carries no pigment.
Check for anything that might increase the strain on the part at that
layer.  It could be a geometry change on the other side of the part,
since that changes the thermal profile of the whole layer.
Must it be ABS?  PETG has a higher working temperature than PLA, but will print
differently than ABS.