For sites using D2L Brightspace, when one or more quizzes do not show in the LockDown Browser Dashboard, it is typically due to a "null" or an empty value in the D2L "Message" field. This field permits you to have a message presented to students upon test submission.  You can see this field by navigating to the course and quiz, then following this click path:

Edit Quiz > Evaluation & Feedback > Customize Quiz Results Displays > Primary View 

This is a sporadic issue with D2L web services and might occur after a course copy. The quickest way to resolve the problem is to enter some text (even a blank space using the space key) in the "Message" field and save the quiz again.  If all quizzes in the course have this same problem, you will likely see this message when opening the LockDown Browser Dashboard:

"There are no deployed tests in this course."

Another symptom of a "null" or an empty value in the D2L "Message" field is that the quiz may experience problems when you try to update it from the LockDown Browser Dashboard LTI tool. Settings may not save correctly. Adding some text in the message field should resolve this problem.

If the default view doesn't seem to be the problem, there could possibly be additional submission views for the quiz that are experiencing the same issue. Deleting those additional views (or using the above technique) may be necessary.