1. Website does not provide logout function: some websites may not provide logout function of personal information or the logout method is not obvious enough, which makes it difficult for users to complete logout operation conveniently.
2. Restrictions on cancellation conditions: Some websites may require users to meet certain conditions before they can cancel, such as completing some unfinished matters or canceling applications within a certain period of time.
3. System failure or maintenance: In some cases, due to system failure or ongoing maintenance, the website may temporarily be unable to provide logout service.