In rare scenarios it can happen that you will see an unfamiliar learning item, created in the past, among the learning items of the Content section of the course. This is due to the change we have introduced with the August 2021 release of how course content is managed.
With the introduction of the united user interface for course content management, we have also enabled all course tools per default. This means, that you won't have to enable Content packages, Quiz, or the Learning module editor for individual courses, before you can employ these tools to create course content.
Before, when these tools had to be enabled before content of their type could be created for a course, it could be a likely scenario that a course admin enabled a tool to test content of this type.
When, for example, testing the Learning module editor, the course admin could create a learning module to test this for a course. If then the course admin decided not to employ the learning module for the course, the course admin could disable the Learning module editor as a course tool and the learning module would automatically disappear from the course as a result.
However, the learning module was never actually deleted. If the course admin would have enabled the Learning module editor tool again, the module would have appeared.
This is what happened when all course tools became enabled with the August release. If a learning item was created in the past for a tool that was later disabled, this learning item will become visible again with this change. However, to not risk disturbing the learner experience, learning items that will appear as a result of this scenario will be hidden by default. Therefore, it will not be visible for learners in any active courses.
As a course admin, you can rest assure that the learning experience you have created will stay the same, and you can tidy up the course by deleting the learning item from the Content section and get rid of it entirely.