Hi Paul,
If you are connected to an external device for sound output, please check the below settings:
1) Set Sound Output to the TV Speaker by going to Settings > All Settings> Sound > Sound Output.
2) Check whether Digital Output Audio Format is set to Pass-Through by going to Settings > All Settings> Sound > Expert Settings > Digital Output Audio Format > Auto.
If you need more help, please contact us at 1-800-SAMSUNG, 8 AM - 12 AM EST, seven days a week, or Chat with us on Samsung.com: https://www.samsung.com/us/support/contact/
~ Samsung Advisor