Apache Guacamole LDAP Tokens -Reading User Attributes

While using an LDAP to store connection data instead of using the database I created a GuacConfigGroup and it's guacConfigParameter is like this:
domain=contoso.com
hostname=${LDAP_POBOX}
password={GUAC_PASSWORD}
port=3389
username=${GUAC_USERNAME}

my guacamole.properties has this on the end of the file:
ldap-user-attributes: PObox, info

The PObox attribute of the user is the IP address of the server I'm trying to connect, when I change the hostname attribute of the guacConfigGroup to the IP or a DNS It connects normally, but when I try to use the AD attribute it doesn't connect and I get this on the guacd syslog:
guacd[31714]: RDP server closed/refused connection: DNS lookup failed (incorrect hostname?)

After some testing using other guacConfigParameters I saw that it's not even reading the LDAP attribute. Followed this documentation to get here