Hi again, @JanetCascio ...
When you say "lockdown", are you referring to the Respondus LockDown Browser? This is a different browser compared to Google Chrome, so I wasn't sure if that is what you meant or not. If they were using the Respondus LockDown Browser, this *might* be a question for their technical support rather than for Canvas Support...because Respondus LockDown Browser would be considered a third-party integration with Canvas.
If students are not using the Respondus LockDown Browser, then I think a call to Canavs Support would be a good idea. Students should use this Guide to contact Canvas Support so that they can get a ticket logged.
How do I get help with Canvas as a student?
Hopefully this will be of some help. Thanks again for the reply.