Support System plugin won't allow the creation of categories

Hello we have the following setup for our servers:

haproxy load balancer, 3 web frontend nodes running nginx, 3 database nodes running MariaDB 10.x Galera Gluster. shared filesystem via glusterfs on the web nodes shared filesystem = document root of wpmanaged.org

we have installed the support system plugin but we are not able to add ( if they get added we get an error like " selected category is not a valid one "