Deleted lessons still appearing

So I deleted a lesson and refreshed, rebooted, logged out, logged in and the lesson is STILL visible within that particular course. The course says that there are 20 lessons, which was previously 21 before deleting one of the lessons, but even though it now says 20, the lesson is still there, as clear as day and can still be opened, read and played etc. Why is this and is there a way to clear it?

Can you please email me course URL to support(at) Thanks!