Steps to reproduce:
1. Create multiple tabs
2. Open a site in 1 of them
3. Right-click Inspect Element on the site so that the element is being masked
4. Select another tab
5. Content under the selected tab is also masked
Wouldn't that be proper to lose the masking on tab change and turn it on once switched back to the inspected page?
*** This bug has been marked as a duplicate of 14254 ***