At the time this was done, the Kanopy model was that when you watched a movie, if you were the first one to watch it from your library, it would trigger an expe

At the time this was done, the Kanopy model was that when you watched a movie, if you were the first one to watch it from your library, it would trigger an expensive purchase ($80–100, as I recall) after which subsequent viewings would be free. This led to unpredictable costs to the library. I think that they’ve since moved to a pay per view model line Hoopla uses which is why movies will sometimes disappear from the service.