As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AUTOPILOT B DISCONNECTED FOR 15 MINUTES AT FL350. F/O NAV DISPLAY ALSO LOCKED UP. UNABLE TO MOVE HEADING INDICATOR COMPLETED MCP LOCKUP, NO HELP. AUTOPILOT AND NAV DISPLAY WAS RESTORED 15 MINUTES LATER. GROUNDED - YES. DFCS BITE LOGGED 22-11607, MCP DATA INV. PERFORMED B737-800 FIM 22-11 TASK 817, ALL TESTS NORMAL REF FIM 22-11 TASK 803.