First, What version of DokuWiki are you using? Your config should look more like
$conf['plugin']['authad']['account_suffix'] = '@domain.com';
Second, everything I've found recommends using authad instead of authldap if at all possible. Fewer settings, and authad is designed to pull AD groups as well, even though I had problems too.
Past that, your AD groups will not automatically show up in the ACLs. You'll have to manually input them. Go to the Access Control List Management, left-click on the namespace you want to assign access to, choose "Group" from the first dropdown, and put the group name in the box using the form @group_name Then set the permissions for that group in that namespace. You'll have to do this for each security group you want Dokuwiki to recognize from AD. For example, I want my Sales team and my Customer Service team to both have read access to the Root Namespace, to have edit access on their respective namespaces, and to have no read access to each other's namespaces. So my settings are as such -
Root Namespace - @user None, @ALL None, @Cust_Serv read, @Sales read, @domain_admins Delete
Cust_Serv Namespace - @user None, @ALL None, @Cust_Serv upload, @Sales None, @domain_admins Delete
Sales Namespace - @user None, @ALL None, @Cust_Serv None, @Sales upload, @domain_admins Delete
Just a heads up - I fought with this for three weeks, running in circles. I eventually had to scrap that Dokuwiki and start over, setting up authad before I did anything else. I have another post in this forum about the issues I was having.
https://forum.dokuwiki.org/thread/12137