What was found
IN CRUISE FLIGHT FL 330, LNAV DISENGAGED, VNAV DISENGAGED. A/C AUTO REVERTED TO CWS - R, ALT HOLD. WE WERE NOT AT A DISCONTINUITY IN FLIGHT PLAN NO LATERAL DEVIATION WERE EXACTLY ON PATH - INDICATION DEVIATION READ 0.0. GROUNDED - YES. ACCOMPLISHED B737-9 IFIM 22-11-00-810-D20 NO FAULTS FOUND OPS CHECK NORMAL.