Hi Deena

Is there any error message you are seeing when you try to login to those websites?

No, when on the login page, after entering password, when I click on "login", there is just no response from the website. Same exact thing on every website affected when using Firefox. Works fine on Edge.

Please can you manually check for any updates to your copy of Firefox.

This support article should help:

https://support.mozilla.org/en-US/kb/update-firefox-latest-release

Double checked that I am updated to the latest version, and I am on 129.0.2, and it says no updates available. One of the sites I'm having trouble with says that it looks like I'm running an ad blocker. I have turned off enhanced protection for the sites I'm having trouble with, and am still unable to log in.

What sites? What happens on google or youtube? Post a screenshot of the issue.

Google, youtube, yahoo are fine. One is example is an online newspaper - when I enter my username and password, then click on "login" - nothing happens - it is totally non-responsive. Another is my security system website - same exact thing. When I immediately move to Microsoft Edge, it works fine, so I know it's not that the website is down. There are no error messages, or anything to screenshot. The login or submit button is just non-responsive after one of the recent updates (I'm not sure which one started the issues).