Forums link on main page leads to 404, is not updated

Hello,

I installed WordPress and wpForo and enabled it, then I configured the forums by adding a few categories.

On the main WP page is a link to the forums, when I click on it, I get a 404.

I don't have apparent issues with WordPress itself, though I haven't tried to add posts yet. Only browsed the configuration panels.

Details on the configuration:

• It's installed on a local Linux VM with an Apache server. The URL of wordpress is "https://<IP>/wordpress" (see details down the post)
• "Turn WordPress to wpForo" is OFF as per default (I don't want that)
• On the dashboard, in Forums / Settings, the default link to the forum is "https://<IP>/wordpress/community", so it correctly detected the /wordpress alias, at least
  • I later tried to change it to "https://<IP>/wordpress/forum" => I see the link on the main page is not updated.
  • If I enter the URL by hand => it doesn't solve the problem, even after a hard refresh (Ctrl-F5).
  • I tried "Delete All Caches" from the dashboard / Forums / Forum Maintenance panel => no change.
• All other settings are the default ones.

Here is an excerpt of the Apache configuration file, in case it's relevant. I need several applications and a default static option, hence the aliases.

<Directory />
    AllowOverride none
    Require all denied
</Directory>
 DocumentRoot "/usr/share/webapps/top"
<VirtualHost *:80>
    RewriteEngine On
    RewriteCond %{HTTPS} off
    RewriteRule (.*)  https://%{HTTP_HOST}%{REQUEST_URI} 
</VirtualHost>
<VirtualHost *:443>
    ...
    <Directory "/usr/share/webapps/wordpress">
        Options Indexes FollowSymLinks
        AllowOverride None
        Require all granted
    </Directory>
    Alias "/wordpress" "/usr/share/webapps/wordpress"
    ...
</VirtualHost>

What else I've tried:

• both with admin login or as a visitor
• from a local computer or from the VM with 'localhost'
• change the permalinks to Numeric

Anyone has an idea of what I'm doing wrong?