Zephyr Squad Cloud REST API not working

Hi Team,
As per the documentation https://zephyrsquad.docs.apiary.io/
The production server on the document isnt working for any API. Its consistently showing HTTP 500 internal server error whereas for mock server, its working. 

In my use case, I need to use production server to make GET API calls to our Jira instance to fetch real time actual data and not mock data.

None of the APIs are working -> Test executions/test cycles list/test folders/serverinfo/licenseinfo.

Also I thoroughly tried to hit the APIs via my NodeJs project and also via Postman but the JWT generated specific to the APIs are somehow suddenly not working at any cost. 

I really need to get it fixed for an urgent deliverable.