I recently tested the integration of Sharepoint online into a custom Microsoft Teams application.
After creating a hub site that contains several child sites, I managed to finalise the integration into Teams. However, I have a bug on the library pages. The hub navigation menu disappears on these pages:
Homepage of my hub site "RDDM intranet" with navigation top bar:
Navigation top bar disappear when I go to the library "Demande aux guichets" (direct link in the hub navigation):
The navigation top bar is however clearly visible in sharepoint online:
Have you already noticed this problem and found an issue?