Hey everyone,
As some of you already noted in this thread, Qobuz has now posted an update on their side confirming what we had been investigating together: the issue was caused by a CDN caching bug affecting hi-res tracks. In some cases, delivery servers were returning a corrupted first chunk, which explains why the problem only affected certain tracks and why switching audio quality could sometimes make playback work.
A number of you also mentioned that things seemed to be improving over the last week or so, and that matches what was happening on the backend. Qobuz ran a full purge with Akamai, clearing the bad cache entries across tens of thousands of affected tracks. That backend cleanup is what restored playback for most users.
At this point, we consider the issue largely resolved. You may still run into an isolated failure while the CDN fully settles, but the underlying cause has been addressed. If you are still seeing widespread problems after today, please let us know.