Good morning, @Swingcoop1 ...

The closest thing I can find in Canvas documentation is listed in:

How do I view a quiz log for a student?

About half-way down this Guide, there's a section called "View Action Log Statuses".  The third bullet point under the screenshot gives a description for "Stopped viewing the Canvas quiz-taking page".  However, as you've said, you're using the Respondus Lockdown Browser.  As I understand it, students shouldn't be able to navigate away from the page if they are using that browser.  So, unfortunately, I'm not exactly sure how else to interpret that message you are seeing if the Respondus LDB is doing its job.  Maybe there are other instructors here in the Community that have used the LDB and have also seen this message and would be able to shed some light on this for you?  Or, have you tried contacting Instructure's Canvas Help Desk staff to see if they would have any insights for you?

How do I get help with Canvas as an instructor?

I hope this info will be helpful to you.  Sing out if you have other questions...thanks!