Lessons that are locked will not appear in the LessonUp or My School search environment. If a lesson does appear, it may be due to one of the following reasons:
Your lesson has only been locked for a very short time. The LessonUp system needs to get your lesson out of the system. This takes around 5 minutes. This is only a question of visuals: a locked lesson cannot be opened by others.
It is not your own lesson, but a copy of a lesson (made by a colleague).