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