voilà l'explication :
Qobuz Library Sync Resolution
Between January 18th-23rd, Qobuz tracks and albums appeared missing from some Roon libraries due to a Qobuz connection issue, which has now been resolved.
Missing content will automatically reappear within 72 hours. No data or favorites were lost.
We apologize for any inconvenience and appreciate your patience
Qobuz Library Sync Resolution
Between January 18th-23rd, Qobuz tracks and albums appeared missing from some Roon libraries due to a Qobuz connection issue, which has now been resolved.
Missing content will automatically reappear within 72 hours. No data or favorites were lost.
We apologize for any inconvenience and appreciate your patience