After standby clone using barman I found an issue to restart postgresql-12 server.

[wasiualhasib]

[postgres@node2 data]$ systemctl restart postgresql-12.service
==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ====
Authentication is required to restart 'postgresql-12.service'.
Authenticating as: osboxes.org (osboxes)
Password:
==== AUTHENTICATION COMPLETE ====
Job for postgresql-12.service failed because the control process exited with error code.
See "systemctl status postgresql-12.service" and "journalctl -xe" for details.

[postgres@node2 data]$ sudo journalctl -xe
-- Subject: Unit postgresql-12.service has begun start-up
-- Defined-By: systemd
-- Support: https://access.redhat.com/support

-- Unit postgresql-12.service has begun starting up.
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.327 EST [3084] LOG: starting PostgreSQL 12.9 on x86_64-pc-linux-gnu, compiled by gcc (GCC)>
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.327 EST [3084] LOG: listening on IPv4 address "0.0.0.0", port 5432
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.327 EST [3084] LOG: listening on IPv6 address "::", port 5432
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.334 EST [3084] LOG: listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.341 EST [3084] LOG: listening on Unix socket "/tmp/.s.PGSQL.5432"
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.351 EST [3084] LOG: redirecting log output to logging collector process
Jan 12 04:10:31 node2 postmaster[3084]: 2022-01-12 04:10:31.351 EST [3084] HINT: Future log output will appear in directory "log".
Jan 12 04:10:35 node2 systemd[1]: postgresql-12.service: Main process exited, code=exited, status=1/FAILURE
Jan 12 04:10:35 node2 systemd[1]: postgresql-12.service: Killing process 3086 (postmaster) with signal SIGKILL.
Jan 12 04:10:35 node2 systemd[1]: postgresql-12.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: https://access.redhat.com/support

-- The unit postgresql-12.service has entered the 'failed' state with result 'exit-code'.
Jan 12 04:10:35 node2 systemd[1]: Failed to start PostgreSQL 12 database server.
-- Subject: Unit postgresql-12.service has failed
-- Defined-By: systemd
-- Support: https://access.redhat.com/support

-- Unit postgresql-12.service has failed.

-- The result is failed.
Jan 12 04:10:35 node2 polkitd[621]: Unregistered Authentication Agent for unix-process:3061:612125 (system bus name :1.215, object path /org/freedeskto>
Jan 12 04:10:39 node2 sudo[3091]: postgres : TTY=pts/1 ; PWD=/var/lib/pgsql/12/data ; USER=root ; COMMAND=/bin/journalctl -xe
Jan 12 04:10:39 node2 sudo[3091]: pam_systemd(sudo:session): Cannot create session: Already running in a session or user slice
Jan 12 04:10:39 node2 sudo[3091]: pam_unix(sudo:session): session opened for user root by root(uid=0)

===========================Note
I don't understand why I am not able to restart postgresql-12 . It is not clear to me where need to update. Anyone please help me on this issue.

@ibarwick do you know where is the issue?