Music Assistant keeps the Audiobookshelf access token on the server instead of handing it out in audio and artwork links. Audio passes through Music Assistant, and a library migration removes tokens from image addresses already saved in the library, listening log and play history.
The connection also exchanges completed and played states more reliably with Audiobookshelf, including changes made in its web interface during an open listening session. Servers older than Audiobookshelf 2.17.0 lose cover images because those versions require the token in the image address.