Tab position after Youtube Full Screen

[DaveC22]

I'm not sure if this is a bug - but it's a frustrating thing.

I'm on FF 49.0.2 with Windows 10 and always have many tabs open - upto 30 - one of which is dedicated to YouTube channels - which I usually watch in fullscreen mode.

I find that whatever the horizontal position of the 'YouTube' tab was before going into fullscreen, when I return to normal view the tab list has been re-positioned so that the YouTube tab now always occupys the right side of the screen - up against the tab scroll right arrow.

I can't help feeling that the tab should remain in its original horizontal position.

[dfoulkes]

I just tested for your problem ... opened up 4 tabs, of which Y.T. was in the middle... started the vid, clicked on full-screen .. then got out of full-screen and the tab was still in the location it started from. So, not sure what is going on at your end... try Firefox in safe-mode to see if it happens...

Try running Firefox in safe-mode... NOTE: This is a testing procedure only ... NOT for normal browsing.
-- On the menu bar, click the Help menu and select Restart with Add-ons Disabled....
Firefox will start up with the Firefox Safe Mode dialog. Click continue in Safe Mode and don't check any items.

Note: You can also start Firefox in Safe Mode by holding down the shift key while Single/Double clicking on the icon.
* (option key while starting Firefox on Mac).
-----------------------------------------------------------------------------------------
>What safe-mode does ..... Safe Mode temporarily affects the following:
* All extensions are disabled. --- * The userChrome.css and userContent.css files are ignored.
* The default theme is used, without a persona. --- * The default toolbar layout is used.
* The Just-in-time (JIT) JavaScript compiler is disabled. --- * Hardware acceleration is disabled.

-- Safe Mode has no effect on the following --
* The status of plugins is not affected.
* Custom preferences are not affected.

This is the link to the main KB article for Safe-Mode ... but, use the above info 1st...
Safe Mode - MozillaZine Knowledge Base

[DaveC22]

Thanks for your reply @dfoulkes.
I experienced the same results as before when I used Safe Mode. I then tried your test - opening just four tabs - and got the same results as you did.

I believe the issue I reported occurs only when there is a significant number of tabs open, and it may also be affected by the position of the tab in question in the list. My problem tab is about half-way through the list - about 15th out of 30.

[dfoulkes]

I just opened 24 tabs where a Y.T. vid was about the 16th tab in line.... started the vid, made it full screen and then hit Esc to go back to normal screen... the tab position did not change... started it up again and went to full screen and then used the icon on the screen to go back to normal size... the tab did not change position... so, not sure what to tell you... maybe there's an about:config setting that is handling all that. You might want to create a test profile and replaces the new profile's places.sqlite file with a copy from your main profile (you have all your bookmarks that way) ... and see if it still acts that way....

Creating a new Firefox profile on Windows - MozillaZine Knowledge Base
And,.... DON'T TOUCH THAT "Choose Folder..." BUTTON! ... unless you fully know all about it.

[Aris]

This is a known problem/bug.

New profile:
- open 30 tabs
- scroll to the 15th tab
- open YT, play a video

(this is how tabs toolbar looks before entering full screen mode)

(this is how tabs toolbar looks after leaving full screen mode)

YT tab scrolled to the right after leaving full screen mode.

[dfoulkes]

So it is specific to exactly 30 tabs?... Maybe the best thing to do then is to open it in a new window.

[Aris]

"30" was just an example. It can be more or less, just tab scroll buttons have to be visible.

[Alice0775]

Probably the problem is scroll position of tabstrip.
The order of the tabs persists. But the tabstrip scroll position is forget after go back to normal sizemode.

I think this is Bug 707079