I found an interesting bug today....
A F2F course requires manager approval, and a user signs up to the course. An email is sent to the manager, and the student - all is good.
However, the student is not given an indication on the screen that they are waitlisted, so they can sign in again.
The big gotcha, is once they sign in a second time, even once they are approved and the status as an admin says booked, the end user still has the status as being able to sign up. They will NEVER see on their screen that they are booked in - they will always get the option to sign up.
Of course, if they sign up again AFTER they are approved, then they get un-booked and put as waiting for approval, and the whole cycle starts again.
This is latest iteration of F2F and moodle 2.4.3+ (Dated this week)