07.09.22, 18:17 +0200 jr:
am fairly new to Debian and am puzzled that the 'sshd_config' file does not have a setting for the 'UsePrivilegeSeparation' keyword. it is also not mentioned in the man page. on another machine (not Debian) I have OpenSSH s/ware installed which provides the option; the READMEs on both machines look identical.
UsePrivilegeSeparation is deprecated since OpenSSH 7.5 (i. e. since 5+ years). You should rather check the state of your other machine - it might be well out of date.
-- Regards mks