Mail App - background refresh locking user accounts?

We are testing an instance of NC20.0.4 (running on RHEL8.3) where we integrate with a moderately sized Active Directory back-end for user authentication. (hundreds of users). We are using the Mail app version 1.7.2

In our mail server logs, we are seeing a NC test user who is attempting to authenticate 4 times each hour (almost exactly 65 minutes), with bad credentials. This behavior began immediately after they changed their password in Active Directory, and happens 24 hours a day. This locks the user out after our local policy of 3 failed PW attempts.

Is there a way to disable background refresh for the Mail app, or force logoff a user session to clear this cached credential? Iā€™ve already tried adding the following lines to my config.php, but it doesnā€™t appear to have logged the user out, as we are still seeing the bad password attempts every hour.

ā€˜session_lifetimeā€™ => 60 * 60,
ā€˜session_keepaliveā€™ => false,
ā€˜remember_login_cookie_lifetimeā€™ => 60 * 60,


I gave up on the mail app, it does not stay in sync with the mail server and it uses vague binaries in the background that eat resources (KItinerary binary). That needs unsafe permissions to run.

Itā€™s also extremely slow, and no it is not my server that is the issue.

I integrated roundcube and used external-sites to add that to nextcloud, have not had issues since.