strange behavior of .pgpass file

Hi,

I found some strange behaviour of postgres superuser password in my
existing cluster, below is the basic outline of the setup.
1. version - postgres 12
2. replication - streaming replication async
3. OS- centos7
4. One Master, One Standby

I have identical pgpass files on both server postgres home directory.

So when I execute below command on slave node:
psql -h slave_hostname/ip -U postgres -d postgres -p 5432 -c "select
pg_is_in_recovery"

I get error of password authentication:

psql: error: FATAL: password authentication failed for user "postgres"

password retrieved from file "/homedirectorypath/.pgpass"

But when I run the same command on master node:

psql -h slave_hostname/ip -U postgres -d postgres -p 5432 -c "select
pg_is_in_recovery"

I don't get any errors and get the expected output as "t".

*Note: the passwords in and path of both pgpass files are identical.*

then why am I getting errors on the slave node for the same command even
after having everything the same ?

Also, I tried the -W to enforce the password of postgres user but got the
same issue on slave and no issue on master although the password is the
same.

What am I missing here ? Please suggest.

Regards,
Atul