Publish QoS2 message Unexpected error

[turtleDeng]

./emqtt_bench pub -c 1  -t aaa -q 2

connected: 1=ERROR REPORT==== 23-Nov-2021::08:40:10.602792 ===
emqtt(MacBook-Pro_bench_pub_2_515772759): State: connected, Unexpected Event: (cast, {mqtt_packet,
                                                                                      {mqtt_packet_header,
                                                                                       5,
                                                                                       false,
                                                                                       0,
                                                                                       false},
                                                                                      {mqtt_packet_puback,
                                                                                       2,
                                                                                       16,
                                                                                       #{}},
                                                                                      undefined})