Connect to Query Web Service Using OData - Use Domain Not IP Address

Hello

I Have created a Web Service that exposes a Query object and NAV has automatically assigned the following URL:
http://ServerName.DomainName.local:9098/DatabaseName/OData/Company('Company-Name')/My_Customers

When I try to consume the Query using the above URL either via Excel or a Browser, my credentials won't work. If, however, I use the IP Address, it works:
http://192.168.50.131:9098/DatabaseName/OData/Company('Company-Name')/My_Customers

On the Nav Service Tier server, the OData Services "OData Base URL" was originally set to blank. I have updated this (and then restarted the service) to http://ServerName.DomainName.local:9098/DatabaseName/OData/ and this hasn't made any difference.

Many Thanks