Get messages from a servicebus queue only retrieves a single message

I have a azure service bus queue which has a number of message's within it. And have a logic-app using a manual trigger. I then add a "Get messages from a queue (peek-lock)" action to the app to get the messages from this service bus and set the maximum message count to "170". But when it's triggered it only picks 1 message. Can someone explain why this is. And why it's not picking up 170 messages.

Thanks