In the update, users launching the browser for the first time after the update are prompted by a dialog box asking them to change their settings to Microsoft’s “recommended browser settings”, which defaults to Bing for search. However, despite users clicking that they don’t want to update their browser settings, they will keep getting prompted anyway.
This is clearly a bug since if this was done on purpose, it would upset many users and could almost come across as forcing users to accept a change they don’t want. There is a workaround that’s being shared on Reddit that lets users disable the prompt through flags. This is not an official solution, but if you do use Edge as your primary browser and hate dealing with this popup, then this is what you can do to disable it until a more permanent solution has been discovered, or when Microsoft eventually patches it.