I restarted firefox today, and now I have the following behavior: I have a window with many tabs open, enough that I have the little '<' and '>' scroll buttons in … (emoñe’ẽve)
I restarted firefox today, and now I have the following behavior: I have a window with many tabs open, enough that I have the little '<' and '>' scroll buttons in the field. Whenever I move the mouse pointer into the tab area (including the scroll buttons, but not the '+' (new tab) button to the right), unless I am actively clicking, the tabs start scrolling rightward until only the rightmost set of tabs are visible. The window being viewed does not change. I can use the 'v' tab selector to the right, and it will select the chosen tab and make that visible in the window, and make the selected tab visible in the tab bar, but when I again move the pointer into the tab area, it starts scrolling to the right. Similarly, I can click on the '<' scroll left button, or double or triple click on it, and it will scroll the tabs leftward; but immediately after completing the action, the tabs will scroll rightward to the end again.
It seems my problem is the same one as in this thread but there was no solution given there (the problem persists after restarting Firefox in troubleshooting mode). I see the same behavior as that poster with the tooltips in the tab bar, but drop-down menus such as on this submission page seem to be working normally for me.