Federated trust for calendar sharing



I'm currently trying to configure Calendar sharing between two domains using microsoft federated trust. I have this working from one domain but cannot get it working from the other domain. The domain it doesnt work on has a Kemp LB in place and i'm wondering if any additional configuration needs to be carried out here.

When running the command "get-federationinformation -domainname *external domain*

I'm getting a SSL/TLS error. See below:

VERBOSE: [13:23:40.461 GMT] Get-FederationInformation : The discovery process returned the following results:
Type=Failure;Url=https://autodiscover.rlbuht.nhs.uk/autodiscover/autodiscover.svc;Exception=Discovery for domain rlbuht.nhs.uk
failed.;Details=(Type=Failure;Url=https://autodiscover.rlbuht.nhs.uk/autodiscover/autodiscover.svc;Exception=The request was aborted: Could not create SSL/TLS secure channel.;);

Any help or guidance would be massively appreciated. Please let me know if you require any other details.