Bounces emails don't go to bounce segment but new mail folders created instead

Your software
My Mautic version is: v4.4.5
My PHP version is: 7.4.33
My Database type and version is: 10.5.15-MariaDB-1:10.5.15+maria~focal-log
OS: Ubuntu 20.04 LTS
Mail service: iRedMail

Your problem
My problem is:

My Mautic is hosted on a normal VPS. Bounce management worked perfectly for the first 205 contacts that bounced. Mautic added them to the bounce segment which has the filter (bounce=yes).

But after that, it stopped working and it started to create a single folder for every bounce email below the main folders (inbox, sent, etc.). I don’t know why this happened. Any new bounce email now doesn’t go to the bounce segment, it goes inside the mailbox a single separate folder as per the screenshot below:

I use Roundcube webmail.

Testing IMAP settings was successful on port 993 and SSL. I couldn’t find any helpful info about this problem. Please if you fixed this error, let me know. It’s really very important to avoid sending to bounced emails.

It’s weird that it worked then stopped working. The bounce segment doesn’t get any new email despite there are many new bounces and even they’re not marked as “dont contact”. I even didn’t do any change to my server or Mautic.

I followed the official documentation here exactly 100%: Bounce management | Mautic

Any help would be much appreciated as I couldn’t find any solution or explanation for this problem.

Thank you very much in advance.