Lessons no showing

Hi guys,
I’ve been trying to create some courses and lessons with LifterLMS. The problem arises when testing the lessons, they just don’t show. I’ve tried creating memberships, access plans, but lessons just don’t show and there is always a message saying “you must be a member in order to view this content”.

Some proof that confirms that what I am saying is true is that when I do a fresh login into a user’s account, it displays the notice “You have been successfuly enrolled to X course”, but I still get the content restriction notice.
I am going to try to deactivate the plugin and try to clear all Lifter tables and do a fresh installation and see what happens.

Thanks