You can check for recently installed suspicious or unknown extensions.

Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

• switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

You can check for recently installed suspicious or unknown extensions. Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or if userChrome.css/userContent.css is causing the problem.

• switch to the Default System theme: "3-bar" menu button or Tools -> Add-ons -> Themes
• do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window

• https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode
• https://support.mozilla.org/en-US/kb/troubleshoot-extensions-themes-to-fix-problems

Unfortunately, none of this seem to have helped

Is it the Yahoo page that opens in a new tab, or the individual results on that page that open in a new tab?

For the latter (individual results), check your Yahoo preferences:

https://search.yahoo.com/preferences/preferences

Is it the Yahoo page that opens in a new tab, or the individual results on that page that open in a new tab? For the latter (individual results), check your Yahoo preferences: https://search.yahoo.com/preferences/preferences

It's when I initially enter what I'm searching for. When I click on one of the links that is a result of the search, it's fine and stays on the tab. It's just the initial search.

Is this only when you are searching in Yahoo when it is opened as your home page (Alt+Home or Ctrl+N)?

My other question is whether this happens when crossing between www. and search., or in other words, is it:

• Starting on https://search.yahoo.com/ the search stays in the tab
• Starting on https://www.yahoo.com/ the search results open in a new tab

Is this only when you are searching in Yahoo when it is opened as your home page (Alt+Home or Ctrl+N)? My other question is whether this happens when crossing between www. and search., or in other words, is it:

• Starting on https://search.yahoo.com/ the search stays in the tab
• Starting on https://www.yahoo.com/ the search results open in a new tab

That's exactly how it is. I have www.yahoo.com as my homepage and results open in new tab. I have tried search.yahoo.com and everything stays in the same tab.

I don't know why having Yahoo as the home page is special. It's just the normal Yahoo page saved in Settings as Firefox's home page, and not a special page generated by an add-on?

It's the same behavior on Chrome when searching from *www.yahoo.com*, they want you to keep their news portal open.