Bitdefender Total Security Update on 04/10/2021 - Facebook

As of the Bitdefender total Security Updates today I now get the Server not found message when I try to log onto Facebook. I have checked the firewall settings and it says that Facebook now has an untrusted certificate. I'm a plu and play computer opporator so have no clue what it means or how to fix it and I can't find anything online. Can anyone help?