I don't know what else to call it. It doesn't look like the corners are lifting of the blue build sheet, it looks like there is too much material is being extruded only at the corners. The layers at the corners curl up. ABS at 220, plate at 110, 1.7mm filament diameter, replicator 4G, .3 layer height, 100% fill, 2 shells, no raft, federate 200....out of the box settings.

TIA KK