How do I remove that exception?
What 'exception' are you referring to? If you visit a site whose certificate has expired, Edge will show you a warning saying so, but giving you the option to visit it anyway - sysadmins (even at Microsoft) sometimes forget to renew certificates, but it doesn't usually take long for them to realize their omission and correct it. The fact that you once visited a particular site whose certificate had expired will not be remembered, so you should see the same warning each time you visit it in a new browser session.
You can check whether the certificate is valid by clicking on the icon at the left-hand end of the address bar. If the certificate is in order, the icon will be a padlock. Depending on your version of Edge, either you will see the certificate icon on the pop-down window that opens, or you have to click on the Connection is secure message to see it. Click on the icon; the certificate's expiry date is given on the General tab of the dialogue.
Sorry if I've misunderstood your concern. Please explain what you mean if I have ...