When I hover over the Firefox icon on the Taskbar (windows are combined) and then hover over the title of an open window I see that window behind the list. However, if I right-click it, nothing happens and I see the window I was in before. Did something different used to happen, or am I using the wrong steps?

(Since I only have one monitor, certain features might be hidden for me.)

So before when you would right click on one of those windows if would bring up a menu.

I took a screen shot of how it used to work with Chrome, it used to work the exact same way with firefox.

Thanks. I'm doing a bug search but I don't see anything specific to this. The developers have been making changes in preparation for having different Taskbar buttons for different profiles, so it could have been broken unintentionally, and maybe that's why I don't see anything specific.

If you have time and patience (!!), you could conduct a mozRegression test to identify what change to Firefox 135 broke this (assuming it started this week). More info on that tool:

https://mozilla.github.io/mozregression/

I used it use it by selecting by release, 134 as last good, 135 as first bad. However, because many intermediate development builds are unsigned, our security software blocks me at some point. Hopefully, it will work for you.

Attached a screenshot from mozregression. If there's anything further I can provide please let me know.

Thank you for doing that. It refer to bug 1934040, which is about the title bar of a window. I guess something about changing the title bar for the window affects the little thumbnails, too.

I have not heard of Windows "Mica" before. It has something to do with transparency, I think.

I submitted a new bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1947324

I'm having the exact same issue since Firefox updated to 135!

The standard context menu no longer appears when right clicking Firefox on the taskbar or right clicking a preview popup, nothing happens at all. The jump list still works ok however I have that turned off on Windows 11 by running 7+ Taskbar Tweaker.

EDIT: Just read the new bug report jscher2000 posted, if you right click go to "Customize Toolbar" and tick the "Title bar" checkbox on the bottom left it resolves this issue for now!

EDIT: Just read the new bug report jscher2000 posted, if you right click go to "Customize Toolbar" and tick the "Title bar" checkbox on the bottom left it resolves this issue for now!

Thanks, this was useful. Not ideal any more visually, but given how often I use the right clicking something I can live with for the moment.