Openldap wildcard certificate install

Question

I have an ubuntu server running openldap to connect to our phones.

A while back I set this to use ldaps with letsencrypt which has worked fine with most things until recently they made a change ref the X3 cert. I am unable to install a late enough version so I can run the --preferred-chain "ISRG ROOT X1 and can't use the snap version as the box ix on lcx and wont run it.

The company has now bought a digi cert wild card certificate and would like this to be on the ldap server, but I can't get it to load the config

The original ldif file I created to import is below with the domain name changed.

dn: cn=config
add: olcTLSCACertificateFile
olcTLSCACertificateFile: /etc/letsencrypt/live/directory.mydomain.co.uk/fullchain.pem
-
add: olcTLSCertificateFile
olcTLSCertificateFile: /etc/letsencrypt/live/test-directory.mydomain.co.uk/cert.pem
-
add: olcTLSCertificateKeyFile
olcTLSCertificateKeyFile: /etc/letsencrypt/live/test-directory.mydomain.co.uk/privkey.pem

I have tried to change the file with modify commands and it's just wont have it and seem to keep getting the below.

SASL/EXTERNAL authentication started
SASL username: gidNumber=0+uidNumber=0,cn=peercred,cn=external,cn=auth
SASL SSF: 0
modifying entry "cn=config"
ldap_modify: Inappropriate matching (18)
additional info: modify/add: olcTLSCACertificateFile: no equality matching rule

Any advise here would be great thanks.