Tab bar RMB glitches

[ChGen]

Windows Terminal version

1.21.2911.0

Windows build number

10.0.26100.0

Other Software

No response

Steps to reproduce

Open Windows Terminal. Do Right Mouse Button click multiple times on the tab, shifting a cursor along tab header area. Note that sometimes you get Windows titlebar standard context menu (like on Alt+Space) instead of context menu of the current tab with completely different set of actions and design.
Also note, that in Dark Mode this system titlebar context menu is always white, while some Windows apps do change system menus to dark mode too (like VSCode, Notepad++, HWiNFO64).

Expected Behavior

While doing right mouse button click on the tab header area, correct type of context menu must be shown.

Actual Behavior

While doing right mouse button click on the tab header area, about 1 in 5 clicks shows Windows titlebar standard context menu (like on Alt+Space) instead of context menu of the tab clicked.

[zadjii-msft]

Oh this is a crazy XAML bug, that I noted once before here: #15744 (comment)

If you right-click on the menu (and then move your mouse off the menu), you get the window's title-bar context menu

lmao that's actually this hilarious XAML bug. If you right click on the shadow of any flyout, you get a system context menu. Literally makes no sense 🤣

I don't think we ever ended up filing this upstream, though we probably should

[ChGen]

It's actually quite annoying bug, since you suddenly get different menu, with different actions and all-white too (in the dark mode) 😁

[carlos-zamora]

Note for myself: this does repro on WinUI, but just WinUI 2 + Xaml Islands