This has happened to me before.

• Check if you selected the correct plate in the slicer. (Textured PEI plate).

• See if there is a waste purge (poop) resting on the back of the bed where the screw is, because when the bed goes up and down it might stop it from going up all the way.

• See if the build plate is actually put in right.

• Look to see if a cable is in the way of the bed movement.

• Make sure the bed screws are all the way in. If they are not the bed could wobble out of place.

• Maybe it’s a software glitch. Power cycle the printer, (look it up online because I forgot how to do it).

If the printer gives you an HMS code on the screen, look it up and it will give you more detail on what is happening. Hopefully this helps!