Yeah, I guess it's obvious from the pic if you zoom in. It's warping and peeling off the bed. ABS wants to be troublesome like that because it was designed to shrink a bit when it cools. Helps it come out of the injection molds. To fight our battle we need to keep abs warm. Heat bed, enclosed and then some help like a brim from the slicer. Could also be that you're still nit close enough when leveling the build plate (matter of a few hundredths of a mm)