I am having an issue with levelling my stock Ender 3 V2. I have followed several different tutorials and I am able to get it fairly level to the point that I can print in the middle 6-7 cm of the bed.
The issue is that the top left and bottom right corners are slightly higher than the top right and bottom left corners (basically the bed seems to be slightly curved as diagonal corners are equal, but one pair of diagonals is lower than the other pair) and I am unable to correct this with the adjustment knobs.
Trying to raise the low corners doesn't work because the springs are held down by the adjacent corners, and the knobs just loosen without raising the bed. Trying to lower the high corners doesn't work because doing so pulls the other corners down as well making them too low.
Any suggestions for how to fix this? Is my bed just bent and I need a new one to be able to utilize the full area?
Some more info: I've also confirmed through measurement in several positions that the x gantry is within 1mm on both ends, and the z supports are at 90 degrees to the frame. is there anything else I should check that might be contributing?