Service Bus Broker Message - Malformed authorization token

Hey,

I've encountered an issue trying to retrieve messages from the service bus. 

The scenario when i encounter this problem is when the app its running on a POS(Point of Sale) in another city. If i run the application on my pc it works perfectly even when i try to run it on a POS in the same office.

The exception i get is this:

System.UnauthorizedAccessException: 40105: Malformed authorization token.

The exception is thrown when i use 

 await SubscriptionClient.ReceiveAsync();

The subscription client is instantiated like this

var runtimeUri = ServiceBusEnvironment.CreateServiceUri("sb", _serviceBusConnectionData.ServiceBusNamespace, string.Empty);
var mf = MessagingFactory.Create(
   runtimeUri,
   TokenProvider.CreateSharedAccessSignatureTokenProvider("key", _serviceBusConnectionData.SecurityKey)
   );
SubscriptionClient = mf.CreateSubscriptionClient(topicName, subscriptionName);

I have no idea why this is happening and i cannot replicate it, it happens only on the POS and that being in another city.

Does anybody have any ideas?