psql trying twice to connect to local DB

I have a local DB (15.2) running in a docker container.

If I make a connection to that DB from most clients I see log entries like
this:

2023-10-07 22:32:26.518
UTC,,,16278,"172.21.0.1:33192",6521dc7a.3f96,1,"",2023-10-07
22:32:26 UTC,,0,LOG,00000,"connection received: host=172.21.0.1
port=33192",,,,,,,,,"","not initialized",,0
2023-10-07 22:32:26.529 UTC,"b2bc_owner","b2bcreditonline",16278,"
172.21.0.1:33192",6521dc7a.3f96,2,"authentication",2023-10-07 22:32:26
UTC,4/340,0,LOG,00000,"connection authenticated: identity=""b2bc_owner""
method=scram-sha-256
(/var/lib/postgresql/data/pg_hba.conf:100)",,,,,,,,,"","client backend",,0
2023-10-07 22:32:26.529 UTC,"b2bc_owner","b2bcreditonline",16278,"
172.21.0.1:33192",6521dc7a.3f96,3,"authentication",2023-10-07 22:32:26
UTC,4/340,0,LOG,00000,"connection authorized: user=b2bc_owner
database=b2bcreditonline application_name=crystal",,,,,,,,,"","client
backend",,0

If however I use psql I see two connection log entries - sometimes almost a
second apart. For example:

2023-10-07 22:33:16.214
UTC,,,16431,"172.21.0.1:48550",6521dcac.402f,1,"",2023-10-07
22:33:16 UTC,,0,LOG,00000,"connection received: host=172.21.0.1
port=48550",,,,,,,,,"","not initialized",,0
2023-10-07 22:33:17.130
UTC,,,16432,"172.21.0.1:48558",6521dcad.4030,1,"",2023-10-07
22:33:17 UTC,,0,LOG,00000,"connection received: host=172.21.0.1
port=48558",,,,,,,,,"","not initialized",,0
2023-10-07 22:33:17.151 UTC,"b2bc_owner","b2bcreditonline",16432,"
172.21.0.1:48558",6521dcad.4030,2,"authentication",2023-10-07 22:33:17
UTC,4/354,0,LOG,00000,"connection authenticated: identity=""b2bc_owner""
method=scram-sha-256
(/var/lib/postgresql/data/pg_hba.conf:100)",,,,,,,,,"","client backend",,0
2023-10-07 22:33:17.152 UTC,"b2bc_owner","b2bcreditonline",16432,"
172.21.0.1:48558",6521dcad.4030,3,"authentication",2023-10-07 22:33:17
UTC,4/354,0,LOG,00000,"connection authorized: user=b2bc_owner
database=b2bcreditonline application_name=psql",,,,,,,,,"","client
backend",,0

The version of psql is 15.4.

Obviously this isn't a major problem, but I'm curious if I've got something
configured incorrectly, or just something I missed from the docs.

Thanks,

Steve