I have what sounds like the same problem (and some similar equipment) as the original poster.
Nucleus+ (build 571)
Netgear CM600 modem…ethernet…
dCS Bartok / preamp etc.
MacBook Pro/10.15.5/Roon (build 571) (wifi)
(Specify what device you’re using and its connection type - USB/HDMI/etc.)
dCS Bartok (ethernet, as above)
Description of Issue
Audio is playing too fast (Chipmunks style, as Mark says). Had played perfectly for several hours on Roon Radio, however — I’d not changed anything.
The same remote plays perfectly (for now at least) to different endpoints, and continues to misbehave on the Bartok when I switch back. Sometimes I wonder if I can prompt this behavior when I move between Roon and Mosaic (for filter choices) apps. But I’m not certain.
Signal path screenshot