I am using the Creality ender 3 v3 SE with eSuns PLA+ in black. The recommended printing temperature is 205-220 and I am printing at 210. The bed is set to 65°. When I print somewhat flat parts. The edges warp off the plate, while the printer is running and the plate is still hot. Until a few days ago it worked perfectly and I don’t know what I am doing different.
It is always only the first few layers, and the print never moves, so that the printer would make spaghetti, its just the edges that lift of a few millimeters.
In order:
Dry your filament.
Wash the PEI sheet on the bed with soap and water. Let dry, reapply glue if you use it.
Verify your bed is actually hitting temp via an external thermocouple and that it’s thermistor isn’t taking a hike and overreporting temp.