When using Q043, there is a retransmission?

[emailsters]

Clien and server are in the same machine and using the loop address, it is impossible to lost udp packets?but there is a retransmission in engine.

./echo_server -s "127.0.0.1:12345" -L debug -c 127.0.0.1,./cert.pem,./key.pem -L debug -o version=Q043 ./echo_client -s "127.0.0.1:12345" -L debug -H 127.0.0.1 -o version=Q043

Logs in client side:

When i print the conn_stats:

[litespeedtech]

You can review both server and client debug log to find out what happened.