IPV6 issue

I have postgres 12 running in centos 7 on my two machines, recently I
changed the authentication of entries of pg_hba.conf to scram-sha-256 for
localhost.

Since then in my one machine, I have started getting the below error when I
use command "psql postgres"

no pg_hba.conf entry for host "::1", user "postgres", database "postgres

I found that localhost is resolve to IPV6 by using below command:

getent hosts localhost

::1 localhost localhost.localdomain localhost6
localhost6.localdomain6

Then I tested the same issue in my second machine

getent hosts localhost

::1 localhost localhost.localdomain localhost6
localhost6.localdomain6

but in my second machine I didn't face any such issue while using command
"psql postgres", I was able to login into the database without such error.

The pg_hba.conf on both machines are identical without having any IPV6
entry in it.

The entry of pg_hba.conf is like below:

# TYPE DATABASE USER ADDRESS METHOD

# "local" is for Unix domain socket connections only

local all all
scram-sha-256

# IPv4 local connections:

host all postgres 127.0.0.1/32 scram-sha-256

I am not able to understand that my both machines are resolved to IPV6 then
why is my first machine is throwing this error ?

Please help.

Regards.