2.9.5+
In the question bank categories the number of questions shows (0) but when I try to delete the category it says there are 233 questions. How can I delete these phantom questions and then the categories.
Regards,
This looks like a case of MDL-29905, which was fixed recently.
This is what I have done in a similar case:
Create a course, transfer the category to this course (via the System category), then delete the course
Hope it helps