I’ve been having a problem where the corners of my 3d print curl up, the first few layers, and the nozzle can run into them and pull the part off the bed. Rather than figure out what the problem actually is, I’ve taken to blasting it for maybe half a second with one of those blue straight flame butane lighters to soften the stickup part and then mush it down with a finger. (You may want to lick your finger before doing this, the plastic is probaby hot.) Generally doing this two or three times across the first handful of layers has been sufficient. Probably doesn’t look great, and it’s more attention than ideally I’d like to apply, but it remedies part-come-off disease.