Is it possible that this is related to the issues identified in a recent Boeing release ""Uncommanded Engine Shutdown during Landing Roll Bulletin""
Samchui.com comment:
"It’s worth noting that a bulletin was released by Boeing not so long ago to pilots and maintenance crew about the Thrust Control Malfunction Accommodation (TCMA) system, which prevents risk in an uncommanded high-thrust situation, stating that errors in the landing sequence could cause the system to activate. The errors include a combination of selecting full reverse too quickly before the aircraft has transitioned to ground mode followed by a quick deactivation of reverse thrust. Boeing advises not to apply full reverse too quickly in the bulletin."