HDMI carries digital audio and video over one connection, but not every port or cable supports every capability. If you use a console, streaming device, soundbar, or receiver, check the specifications for both ends of the connection. A device can only use a feature when the display, source, and connection path all support it.
Look for labels that identify enhanced bandwidth or audio return features, and consult the device manuals when port names are unclear. HDMI ARC and eARC let compatible televisions send audio back to a soundbar or receiver through an HDMI connection. For a console or computer, features such as high refresh rates depend on the capabilities of the display and the selected port, not simply the cable's appearance.
Choose a certified cable appropriate for the distance and signal requirements, and avoid unnecessary adapters or long cable runs when troubleshooting. Connect the devices firmly, select the correct input, and enable any required format or enhanced-input setting in the menus. If a screen stays blank or audio disappears, test one device and cable at a time. Restarting connected equipment can also help it renegotiate the connection.