Are these security prompts like CAPTCHA tests and sending you a code to verify your identity? Do any of the error messages refer to cookies? Firefox 96 modified when cookies can be sent "cross-site" to conform to how it is done in Chrome and Edge. Obviously there are some site compatibility issues. (For example, Bing doesn't send Firefox the same cookies it sends to Chrome and Edge.) To test whether this is the problem, you can temporarily roll back the main change to the Firefox 95 setting. This requires going under the covers: (A) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.'' (B) In the search box in the page, type or paste '''laxByDefault''' and pause while the list is filtered (C) Double-click the '''network.cookie.sameSite.laxByDefault''' preference to switch the value from true to false Most likely, that will take effect immediately, but in some cases, you might need to clear existing cookies for the site or quit Firefox and start it up again. Hopefully we will get a better understanding of how to set site-specific exceptions in the future so users can benefit from higher security on compatible sites.