By Audio Settings are you talking about Windows Settings or Windows Sound Panel?
Open Windows Sound Panel and right click any enabled Sound device. Then click on Sub-menu to show all disconnected or disabled Audio devices:
Do you see your headphones under either Disabled or Disconnected Devices?
Also go to Device Manager and see if there are any errors or Yellow Exclamation marks and see if your headphones are listed and recognized.
Try connecting your USB headphones to a different USB Port on your computer in case it is a bad port.
To rule out a defective USB Headphones, try using another USB Headphone and see if it works.
Try installing a previous AMD Driver in case the latest is the problem from here: https://www.amd.com/en/support/previous-drivers/graphics/amd-radeon-r7-series/amd-radeon-r7-300-seri...