As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK DUE TO NR 5 L/E SLAT INTRANSIT INDICATION OCCURS INTERMITTENTLY OF FWD PANEL AND OVERHEAD LED PANEL WITH FLAPS EXTENDED INFLIGHT. FOUND LOOSE ROLLER ON NR 5 SLAT INBOARD TRACK. REINSTALLED ROLLER PER BOEING MM. (LPG 243950)