User 'root' fails to run command 'mount' with error "mount: only root can ... "

Issue

• User root fails to run command mount with errors below:

# id root
uid=0(root) gid=0(root) groups=0(root)

# mount -a
mount: only root can use "--all" option (effective UID is 1002)

# mount -vvv /dev/mapper/rhel_test-home /home
mount: only root can do that (effective UID is 1002)