Issue accessing remote web service port from a Windows Server box

I have an issue where every laptop and phone I have access to can access a 3rd party remote URL (which contains WCF service) at an address like: http://example.com:17001/ServiceName.svc

This can be accessed in a browser by every device we have access to except a Windows Server 2008 box which is the one we really need to access it from! The server gets an 'ERR_CONNECTION_TIMED_OUT' on Chrome. We also tried to connect via telnet and psping but can't get access to port 17001 (which is open). We can ping the domain & IP no problem. I've spent today trying to figure out why, and have gone through the usual suspects of disabling firewalls and anti-virus on the Windows box and disabling a lot of Windows Services to try to find the cause.

My question: what would cause a single client to not be able to access the remote URL:port, while every other device can? Any ideas would be appreciated.