What can cause the center of the bed to be higher than the sides? I find it impossible to level the printer recently. I read a couple of articles on bed warping but that refers to having the center of bed lower than the sides (collapsing on its own weight warm up after warm?) but what I experience is the opposite: the center is higher than the sides. Did anyone face this situation and how did you solved it? I use an Anycubic Chiron so the bed is pretty big.
As the Anycubic Chiron has an automated bed leveling, you can just calibrate that differences in height in the printer's firmware. Here is the official tutorial made by Anycubic :)