Sample screenshot below for Sniffer issue:

1. Open “Display settings” in your browser, and make sure the Resolution is the system recommended one, or choose 100% of “Scale and layout"
2. Clear browser cache and reopen the course on Learning Hub for confirmation.

If you still encountered same issue, please provide required information below for our further investigation.
1. Learning Hub account/email:
2. Course name & code:
3. Screenshot of error
4. Screenshot of Resolution of your device
5. Screenshot of Zoom setting of using browser