cant connect to localhost:5432 (but unix socket ok)

Hello all,

My database is not listening on TCP/localhost, desptite it is listening on
the unix socket. How can I investigate this?

I could have done something that is out of my understanding because I have
been loading some big pg_dumpall files that might contain administrative
changes that I am not fully aware of.

Here are some details about the connection issue:

root(at)deb10tp:~# id
uid=0(root) gid=0(root) groups=0(root)
root(at)deb10tp:~# su postgres
postgres(at)deb10tp:/root$ id
uid=116(postgres) gid=126(postgres) groups=126(postgres),125(ssl-cert)
postgres(at)deb10tp:/root$ cd /
postgres(at)deb10tp:/$ psql -h localhost
psql: could not connect to server: Connection refused
Is the server running on host "localhost" (::1) and accepting
TCP/IP connections on port 5432?
could not connect to server: Connection refused
Is the server running on host "localhost" (127.0.0.1) and accepting
TCP/IP connections on port 5432?
postgres(at)deb10tp:/$ psql
psql (11.9 (Debian 11.9-0+deb10u1))
Type "help" for help.
postgres=#

Thank you
Joao