Bed warped suddenly?

[EagleSeven]

??? There are spring-loaded adjustment Screws at all 4 corners of the bed-plate, under it .
Are you saying that those will not adjust the bed height correctly ?

(the springs may have caused the change)

Those screws normally have Wing-nuts on them that can be a little difficult to adjust,
so I printed some knobs to replace the wing-nuts, which I downloaded from thingiverse.com

I suggest that you add a piece of glass to top of bed-plate, if you have not done that already.
Glass will correct any warping in bed-plate.
(glass is held on with same Aqua-net spray as used to hold printed objects on glass)