Persistent Ghost Tabs appear on Windows' Taskbar with dual displays

[Stef-UK]

Environment:

• Firefox: 137.0.2
• Windows 11 Version 24H2 (OS Build: 26.100.3775), Experience Pack: 1000.26100.66.0
• Windows Settings:
•     Dual monitors present.  System > Display > Extend these displays
•     Personalisation > TaskBar - Taskbar Behaviours - Show my taskbar on all displays = ON

Bug (1):

• Start with  "Show my taskbar..." setting OFF, and Firefox active on 2nd display only, 3 open tabs.
• Enable the  "Show my taskbar..." setting via Windows settings
• Hover the cursor over the FF icon on the 2nd display's taskbar.  You will see duplication (2x3) open icons appear above the taskbar (PIC-1.jpg).

Bug (2):

• Start with  "Show my taskbar..." setting ON, and Firefox active on 2nd display only, 3 open tabs.
• Close one or two FF tabs and hover the cursor over the FF icon on the 2nd display's taskbar. You will see 'ghost' icon(s) representing the closed tab(s). (PIC-2.jpg).

Effects

1. Such 'ghosts' do not disappear, even if you close and re-open Firefox.
2. They do not appear if you hover the cursor over the Firefox icon on the taskbar of the primary display
3. They do not appear if you turn OFF the "Show my taskbar..." setting via Windows settings.

[L3x]

Yes, unfortunately, this bug really annoys me too.
Only on Windows 11 and currently affects two applications (Mozilla Firefox + Adobe Reader).

I use three monitors.
If you open Firefox on one screen and drag it to another, multiple tabs appear in the taskbar.
If you drag Firefox back to the main screen, it works, and it's stacked - correct.

The only solution so far has been to close and reopen the browser.

As I said, it only affects the two software solutions so far.
I hope either Microsoft, or more likely Mozilla and Adobe, can fix this.

[dds]

I'm experiencing the same issue with Firefox. I'm using two monitors, and even though I keep all the windows on the same monitor, ghost windows still appear.

[DarioViva]

It's even worse when items in taskbar also show their title.
Bug on Bugzilla: https://bugzilla.mozilla.org/show_bug.cgi?id=1986589

[Tri4L]

Same problem here, tab display bug on dual monitor.
Firefox 143.0.1 
Win11 24h2