Roundcube installer refuses to recognize my smtp password

[HankM]

I have a working Postfix/dovecot mail server running on Alma Linux 8.6.

I installed Roundcube according to the how-to https://www.linuxbabe.com/redhat/install-roundcube-webmail-centos-8-rhel-8-apache-nginx

I'm using apache. This is a newly installed server so everything is up to date.

Everything checks out when I run the installer, EXCEPT the smtp test config refuses to recognize my password. It recognizes it for Dovecot,. It's the correct passweord because I'm using Thunderbird on my windows PC using STARTTLS and normal password and the password is correct.

So close, yet so far away.

Cna anyone help?