Why you using USB? It’s Roon Ready over a network connection you don’t need to USB. If you are what are you plugging into it and is it into the correct USB input ?
Thanks for taking the time to write in and share your report! Welcome to the community as well, we’re excited to have you here.
@CrystalGipsy makes a good point above, you do have the option to stream over Roon Ready, which would definitely be the best use of your Marantz device! Here’s more info on Roon Ready:
Let me know if this makes sense and if you have any additional questions along the way.