Covered by the newly created Behat test. Manual testing is below. Initial setup Log in as admin. Create a course called C1 or use an existing one. Navigate to the Question bank of the created course. Create a category called Cat1 is a subcategory of Default for C1 category. Create questions as below Question type Question name Tag Category True/False Question name A foo Default for C1 category True/False Question name B bar Default for C1 category True/False Question name C foo Cat1 Testing Log in as admin. Create a Quiz called "Quiz with random questions" for the created Course. Navigate to created Quiz > Edit Quiz (or Questions in the secondary navigation of Moodle 4.0). Click Add link and click 'a random question'. Change the Category to Default for C1. Make sure the Include questions from subcategories too option is not ticked. Verify that you will see Question name A and Question name B. Expand the Tags filter. Verify that you will see foo and bar . Click on foo. Verify that the popup will be reloaded. Verify that you will see Question name A. Verify that you will not see Question name B. Click on Include questions from subcategories too. Verify that the popup will be reloaded. Verify that you will see Question name A. Verify that you will not see Question name B. Verify that you will see Question name C.