That can be frustrating. I'm wondering for how long your calls have been unanswered. Have one, two, three days or more passed? Did you try to text or email the agent?
Unresponsive agents is the number one consumer complaint most years. I am located in California and work with Orange County Real Estate sellers and buyers so I can't speak to parctices in your specicifc are.
If more than 48 hours have passed since your first contact attempt, try calling the agents office and speak with the manager or broker. There may be a compelling reason for the lack of response.
Good luck with you search.