Thank you, I will try to post screenshots tomorrow. For now, just in short:
I have 5-6 devices in the main list, four of them incl. Oppo have 'WASAPI' in brackets. Under 'More...' the four are repeated, incl. Oppo, but with 'Direct sound' in brackets. On the main list there is one with 'Asio' in it's name, something like 'foo_.... _asio'.
If I choose '... asio' or 'Oppo... Direct sound', playback results in the error message.
With 'Oppo.... WASAPI' everything is perfect except DSD512, which plays with beffering interruptions and Oppo doesn't show DSD but PCM.