Zoom and Cross-Site Tracking in Safari
When using Safari on a Mac, those accessing the Zoom tab within Canvas may see an error that says, "Sorry, your session was expired. Please refresh the page or login again." This may be due to cross-site tracking being blocked. The steps below may help you to resolve this error.
In Safari click Safari , and choose Preferences 
Choose Privacy , and you will see that Prevent cross-site tracking is checked. You will need to uncheck the box, Prevent cross-site tracking .
If your preference is to keep prevent cross-site tracking turned on (checked), consider using a different browser to access the Zoom tab in Canvas. For Canvas to run most effectively, be sure that you are running the most up to date version of any browser.