SSL issues with -sb.accesscontrol.windows.net URL (service bus)

[hill79]

I had been using the sdk to pull messages from a number of Service Bus queues for over 12 months, but a few months ago the script started failing with the error below (where 'xxxxx' is our domain) which to me suggests an issue with the SSL certificate validation.

"Fatal error: Uncaught GuzzleHttp\Exception\RequestException: cURL error 51: SSL: no alternative certificate subject name matches target host name 'xxxxxxxxxx-sb.accesscontrol.windows.net'"

I'm a PHP dev, so I'm not familiar with the admin side of Service Bus / Azure at all, all of that is taken care of by 3rd party IT. Currently, they're blaming the code (ie, the sdk) for the problem, but I'm not sure thats the case as others seem to be using it without issue.

If anyone can cast any light, or give me some hints at where the issue originates, I'd appreciate it.