A disabled user which is a memeber of a group which has 'Use Confluence' permissions is still counted towards the license limit.

The expected behaviour is that a disabled user does not count towards the license limit, regardless of what groups that disabled user might have been a member of. It would be understandable if re-enabling such a user might return an error if that user would then breach the licensed limit.

We worked around the issue by removing all disabled users from all groups, but that's effectively historical data loss (in addition to being unintuitive).