Hello @John_Roberts,
Thanks for contacting support, while we don’t do any in-house testing with JRiver, I will try my best to can get you up and running here. My initial question is does Jriver work through any other apps on your computer, or is this behavior only exhibited through Roon? I have heard reports that the ASIO driver for JRiver may a little more stable than the WDM, do you by any chance have that as an option in Roon Audio Settings and can give that a try? Although it is not likely related can you please check to see if enabling this compatibility feature triggers any change in behavior? Located under Settings -> Audio -> Cogwheel Icon next to JRiver -> Device Setup -> Advanced Settings -> Work Around Devices that Misreport Capabilities.
Please let me know your replies to the above when possible.
Thanks,
Noris