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.
Has your living space gotten cooler, or are you opening a window that you weren’t before, or have you started running AC or a fan near your printer? The ambient air temperature and especially drafts will affect the cooling rate of the plastic, which will contribute to shrinking. If you can, block the area around the printer and/or get an enclosure for it.
Are you cleaning your print bed regularly?
Have you run actual temperature tests with this particular filament?
Have you releveled your bed?