As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SATCOM USED INFLIGHT. COULD TRANSMIT ON ONE BUT COULD NOT HEAR. COULD HEAR ON TWO, BUT COULD NOT TRANSMIT. ACFT GROUNDED. PERFORMED SATCOM COMMUNICATION SYS TEST IAW MM 23-1500-730-801, SYSTEM TEST IS GOOD BOTH NR 1 AND NR 2 RECEIVES AND TRANSMITS.