I use Bitdefender as antivirus program. When I start up Firefox the antivirus program blocks the start up because it says Firefox is trying to access a program (sync.contextualadv.com) which does not have same authentification as the target. It gives me choice to accept this as an exception if I want. I don't understand the details but I don't want to allow this to proceed until I'm sure it is safe. I'm on an HP computer running Windows 11. I use firefox on another laptop running Windows 10 and have not had this problem.