iRedMail's login takes over other subdomain's webpage:

iRedMail 1.6.8 downloaded on fresh Debian 11 install with MariaDB 15.1 and nginx 1.18.0, then downloaded Mattermost-9.5.2-linux-amd64 using Postgresql 13.14, all on Hostinger KVM1 VPS.

Not using iRedAdmin-Pro.

In other words, mm.example.com and mail.example.com look alike.

Screenshot attached:

Couldn't solve with this info: docs.iredmail.org/file.locations.html#nginx I looked at Roundcubemail config files, so far, as well as uWSGI docs.

Interestingly, curl ftp(snip)mm.example(dot)com yields:           (with ftp in place of 'eitch tee tee pee')
-bash: curl ftp(snip)mm.example(dot)com:                               (and 'S' in place of 's' for emphasis)
301 Moved Permanently
301 Moved Permanently
nginx

and curl ftpS(snip)mm.example(dot)com yields: (arrows deleted, parentheses instead)
‘(html)(head)(meta HTTP-EQUIV=“REFRESH” content=“0; url=/mail/”)(/head)(/html)’

but curl ftp://#.#.#.#:8065 yields html appearing to be the correct Mattermost login page,
as does
curl ftp(snip)mm.example(dot)com:8065 and
curl ftpS://#.#.#.#:8065

yet curl ftpS(snip)mm.example(dot)com:8065 yields:
curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number