I have an Ender 3 Pro with the magnetic mat that is heated. The filament is Inland PLA+ Luminous Green. I've set the bed at 50 and 65 degrees and both times the print will start too warp and peel up in a corner of the print. I was printing a flat lithophane and two corners just started to come up off the bed, bend up so much that the extruder hit the piece and knocked it all off the bed.Has anyone experienced this? Are my settings wrong? Too hot? Too cold? Just a bad filament brand? Bad filament type to print flat items?Thanks for any help!