My first comment is to change your Oppo’s Output volume from Variable to Fixed.
The Signal Path shows that it is leaving Roon and going to your Oppo just fine. You have set Roon to send the file untouched to the Oppo and it is doing that. The Oppo should be doing the full decode, but, it is not.
Is your Oppo’s firmware up to date? You might also take a look at this thread…