OK - after 35 years without a serious stereo system, I finally bit the bullet and invested in a modern system last weekend
I have a new Bartok, a Tube Amp (Rogers High Fidelity) and Wilson speakers. Got everything installed and everything seemed to be working perfectly. I set up a MinimServer on my Synology box to access my own library and I have trials of Tidal and Qobuz
Today, when I selected uPNP, the Bartok could not find my Synology server. I confirmed it was running (and indeed I even restarted it, but to no avail)
Much worse, after testing some tracks with Tidal, I switched to Qubuz to try some tracks there. I then switched back to Tidal and tried to play the same item (Brahms Violin Concerto, Anne Sophie Mutter). It played, at what seemed like double the speed and an octave too high. Selecting other pieces of music worked fine but everytime I tried to play that Concerto, it was double speed and octave too high.
Switching to standby had no effect. I had to unplug the power cable and basically power cycle the Bartok after which point it both played properly and was able to find my Synology library.
This is not what I would expect with a brand new $18,000 device.
What happened and how do I prevent this from happening again?