Web Appliance - AD Authentication Could not test LDAP settings

Good Morning all,

I have never had any problems with our Sophos Web Appliance, up until now:

We had to turn off AD autnetication and turn it back on, now we cant complete the verify settings section, due to "Could not test LDAP settings'

I have tried the below and i am in talks with Sophos directly, but they are not giving me any good roubleshooting tips:

We are unable to authenticate an AD user to either of our DC's inc the global catalogue server.

We have created a brand new user

We have added that user to the domain permissions as outlines in the Sophos whitepaper installation

We have added that account into DA permission group

We have a Sophos Email Appliance that uses AD authentication through LDAPS to the above DC’’’’s without issue.

We have re-IP’’’’ed and re-VLAN’’’’ed the Sophos appliance so that it sits on the same VLAN as the DC’’’’s.

We have entered all details on the Sophos Active Directory screen manually (DN’’’’s etc )

Any help would be greatly appreciated,

San.