first of all thank you very much for the help
now since you mentioned the uid i tried to revalidate these findings as first time i did not bother to change anything else than just the creation of a second admin.
so with different uids as i said to me it looks that only the lock database override works.
now i deleted the second admin and recreated it with uid=0 (in the show configuration output is with this line "add user chris uid 0 homedir /home/chris") and it looks to me that none of those two commands work now running from this second admin
fw1> show config-lock
Configuration locked by admin from 192.168.1.120, facility command line, 291 seconds to expiration
fw1> lock database override
fw1> show config-lock
Configuration locked by admin (300 seconds to expiration)
fw1> unlock database
fw1> show config-lock
Configuration locked by admin (300 seconds to expiration)