I think there’s a glitch regarding content I own.

You are most likely benefiting from someone in a campaign you’re in activating Content Sharing and sharing that content with the whole campaign. As your Character is part of that campaign, you can access that content for that character and can read those compendia.

You misunderstand the meaning of “campaign” in this context. If you are in any DDB campaign (regardless of which module it is, or even if there is no module being used) and if content sharing is enabled for that campaign, then all content owned by anyone in the campaign (DM or player) will be shared with everyone in the campaign.

You see, the system has absolutely no idea that you’re DM is using Descent into Avernus, or Strixhaven, or Curse of Strahd, or none of the above. All it knows is that you’re in a campaign with certain other users, and that content is being shared within that campaign. So it shared all content within that campaign. Make sense?