As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
MIA - CREW REPORTED DURING CLIMBOUT GOT LEADING EDGE SLAT ASYMMETRY EICAS MESSAGE AND WARNING LIGHT ILLUMINATED. FLIGHT RETURNED MIA LANDED WITHOUT INCIDENT. AIRCRAFT REMOVED FROM SERVICE. REPLACED NUMBER 9 SLAT SENSOR LOCATION R023. SYSTEM GROUND CHECK NORMAL OPERATION.