pg_read_all_stats and pg_stat_replication in postgres 10.

Hello,

In Postgres 10 (release version installed from apt repo on Debian 9), the
following columns of the pg_stat_replication view are returned as null for
a user who has been granted pg_read_all_stats:

state
sent_lsn
write_lsn
flush_lsn
replay_lsn
sync_priority
sync_state

Other columns (like client_addr, backend_start) have valid values. Other
views (like pg_stat_activity) also have valid values. Granting pg_monitor
does not help. Only superuser is able to retrieve these values (like it was
in 9.6).

Is this a bug?

Thanks,
-Mahadevan