Unknown host error when doing api calls

The website i am developing on recently change IP address via their hosting company.

Now i get an unknown host error when using the api (see image)

I have an adobe developer account and i'm using a developer test key for the api calls, i have tried creating a new key but that doesn't work.
Can anyone advise on how i might resolve this or whether i need to change anything in the adobe account to fix this?
Thanks in advance, Rob