Ive checked the connections, they are all good, voltage is correct, and no bent pins
it bases the levelling on the CRtouch sensor and the strain gauge at the front left of the bed. Double check the strain sensor connection, it involves dismantling the bed, a little involved as the spacers are of differing lengths. Double check the CRtouch is connected correctly. CRtouch could fail as could the strain guage. Might need to contact Creality.