"New Tab" in Firefox is construed to mean a new, blank tab, not a tab opened from a particular website.

There's a hidden preference browser.tabs.insertRelatedAfterCurrent, which when set to True (the default value) forces new tabs being opened that are related to the current domain, to open to the immediate right of the current tab. That pref may be in the UI of a "tab related" extension, and not be hidden in about:config .

When I do the said modification, the New Tab still opens as the first Tab. However, when I open a website's page in a New Tab, it simply sends that Tab to the very front.

After resetting the "browser.tabs.insertRelatedAfterCurrent" to "True", it does not help with my present case - opening a webpage in a New Tab (from an existing Tab) still opens to the immediate left of that Tab.

It doesn't occur only for New Tabs. In fact, whenever I open up Firefox, the order of my Tabs would appear backwards. This means that every time I open up my previous session with Firefox, the order strangely goes backwards.

A temporary solution I found is to open a New Window, close the affected Window and reopen it - the affected Window's Tabs would show in the right order. A more permanent solution to this strange behavior would be appreciated in addition to the main concern over the Tabs' behavior of opening to the immediate left.

A temporary solution I found is to open a New Window, close the affected Window and reopen it - the affected Window's Tabs would show in the right order.

Sound like some sort of "session restore" for the Window that was closed and re-opened, but the built-in session store functionality doesn't "restore" when another window is left open. I have no idea what that it about or how that is happening, unless you are using multiple homepages.

Do you have any tab related extensions installed?

Better yet, how about providing information from about:support Troubleshooting Information using Copy text to clipboard, then editing to remove all but the Extensions information.

I see.

Could you please give me instructions on how to do that? It would help me out.

Also, as for tab-related extensions, I'm not certain if I do have any. Apart from AdBlock Plus - which is actually an Extension - I don't have any Extensions that could affect my Tabs' behavior.

So based on what you suggested, would this Extensions information help my Tabs problem? The details are below.

Hopefully, any helpful advice from this can provide me with the necessary action plan to restore my Tabs' original behavior.

Extensions

Name: Activity Stream Version: 1.1.4 Enabled: true ID: @activity-streams

Name: Adblock Plus Version: 2.7.3 Enabled: true ID: {d10d0bf8-f5b5-c8b4-a8b2-2b9879e08c5d}

Name: Min Vid Version: 0.3.0 Enabled: true ID: @min-vid

Name: Multi-process staged rollout Version: 1.3 Enabled: true ID: e10srollout@mozilla.org

Name: No More 404s Version: 1.5.6 Enabled: true ID: wayback_machine@mozilla.org

Name: Page Shot Version: 0.1.201609222137 Enabled: true ID: jid1-NeEaf3sAHdKHPA@jetpack

Name: Pocket Version: 1.0.4 Enabled: true ID: firefox@getpocket.com

Name: Tab Center Version: 1.25.0 Enabled: true ID: tabcentertest1@mozilla.com

Name: Test Pilot Version: 0.8.5-tag-2016-09-27 Enabled: true ID: @testpilot-addon

Name: Tracking Protection Experiment Version: 1.0.1 Enabled: true ID: blok@mozilla.org

Name: Universal Search Version: 1.0.11 Enabled: true ID: universal-search@mozilla.com

Name: Web Compat Version: 1.0 Enabled: true ID: webcompat@mozilla.org