Firefox and Taskbar

It's probably not a very important issue, but still somewhat annoying, so I would be very grateful if anyone has an idea.

I have several browsers installed (used for different purposes). Some are pinned to the taskbar, as shown in the attached images. Now the issue that I'm having: once I open Pale Moon or Firefox Nightly, the pinned icon on the Taskbar transforms into a bar - don't know how it's called -- showing the corresponding browser window. Same does not work with regular Firefox, it opens same bar separately, keeping the pinned icon.

Can anyone explain how that happened?

Nothing helpful there, I'm afraid.

That's not what I'm looking for. This is a general setting, not specific to Firefox. The result looks like this



Now, what I'm looking for is to have the taskbar organized as in my original post, and for Firefox Nightly and for Firefox Beta (as well as Pale Moon) it works just fine, namely, once I open the browser, the taskbar button expands and shows an informative label (typically, the current open tab). With Firefox proper this does not work, as I showed - instead of expanding the taskbar button, it adds another label to the taskbar. My suspicion is that there is some setting somewhere in Firefox that controls it, but I can't think of anything, which is why I posted here (as opposed to the general support forum).

I finally found a solution: when you install Firefox, it adds a shortcut to the Start Menu. Apparently, both Firefox and Firefox Beta create a shortcut named "Firefox" (in contrast, Firefox Nightly creates a shortcut named "Firefox Nightly"). This seems to be to cause of the issue I was describing.

The solution is to unpin all of them from Taskbar, rename the shortcut in the Start Menu from "Firefox" to "Firefox Beta" (in fact, you can rename these shortcuts any way you want, the important thing is that two shortcuts should not have the same name), and pin them back to Taskbar.