I had some issues with 24/192 ALAC files playing on my Oppo UDP-203 a few months ago after the latest firmware update. They were all playing with enormous amounts of distortion and stuttering, regardless of medium. USB stick, LAN, etc. all the same issue, which isolated it to the 203. I also have an older 103 and it played the same files from the same USB stick just fine. Contacted support, who were very responsive and agreed the issue was occurring (I sent them a video demonstrating it) but ultimately nothing ever came of it. One of the other smaller issues is that it will play one song at a time from JRiver, then stop. I have to keep going to the Overview and manually start each song in the playlist. It had become quite maddening.
I ended up grabbing a Marantz ND8006 CD/Streaming player and have not looked back. It sounds better and functions better as a music streamer. Zero issues with JRiver. The Oppo 203/205 is an outstanding BluRay player and for streaming movies from JRiver it's terrific. As a music player not so much. The DAC in the Marantz is killer. I have it and my receiver in "Pure" mode, and use the iPad app to choose what I want to play from JRiver on my iMac.