How do I un-accept unmatched security certificate warning

A client's web site is giving an "unmatching security certificate" error in BitDefender Total Security.

I first took the option to accept the error and "take me there anyway". This let me check that the web site is still functioning normally.

Now I want to check for when the certificate error is fixed - for which purpose I now want to see the error again.

The problem is that I can't. This site has now been "registered" as OK: and the warning no longer appears. I need to be able to to un-accept the warning: so I can see it again.

How do I do that?

I have tried Manage Exceptions in Bitdefender, but the site is not listed as an exception !!

Where do I go in Bitdefender so that I will again be blocked when attempting to go to that site ?