Yep, happens with my WiiM setup as well. I've reported it to both WiiM and Qobuz. Typically, grouped WiiMs will get through one or two tracks flawlessly, and then there'll be considerable distortion on subsequent tracks. My gut feeling is that changes in the bit rate/depth between tracks sent by Qobuz trigger the issue. I'll be doing more tests to try and ascertain whether that's so, or if it could be something else.
Tidal Connect under the same circumstances doesn't have that issue -- did it at first? -- which encourages me that WiiM can figure this out and make it work properly.