If the corners are lifting off the plate, or the plate is lifting off the bed, the problem is not a warped bed.
Warped beds were a major problem with printers produced in the first half of 2023, but they are very rare since then. Prints and plates did not lift from a warped bed, and the automatic “leveling” maintained proper layer thickness, but the print followed the curve of the bed, and would not sit flat on a flat surface.
I posted my measurement method in a very long thread at the time: Warped bed :( seems like a common QC issue - #1375 by lkraus, but there are other methods mentioned in that lengthy thread.