I am having the same issue that a different post with this title.
All of my scorm packages are showing No students enrolled in this course yet Nothing to report.
In the other post you ask if the roles have been customized. That is not the case here. this is a recent upgrade to Moodle 3.4 and this behavior started then. That upgrade required an upgrade to php as well from my understanding so the entire previous moodle site was backed up and then restored into the upgraded site.
Any help is appreciated.
Thanks
Tim