When I right-click an app icon pinned to the taskbar, the jump list doesn't appear.

I have what appears to be a reproducible regression affecting the taskbar Jump List/right-click menu on one Windows 11 25H2 desktop.

Symptom:
Right-clicking any pinned taskbar application causes Explorer to freeze for approximately 30 seconds. During the freeze, the Jump List does not appear (or appears only after a long delay). Left-clicking the pinned app generally works normally.

What does work normally:

• Right-click on the Start menu.
• Normal Explorer context menus (desktop/files/folders).
• General system stability.

Testing performed:

• Build 26200.8037: problem does not occur.
• Build 26200.8875 (KB5101650): problem occurs immediately.
• Build 26200.8894: same problem.
• Build 26200.8973 (KB5101684 Preview): same problem, despite release notes mentioning Explorer/Jump List reliability improvements.
• Rolling back to 26200.8037 restores normal operation every time.

Comparison with another PC:
I have a second Windows 11 machine (laptop) running 26200.8973. It does not exhibit this problem. Right-clicking pinned taskbar apps works normally there.

Other observations:

• Restarting Explorer does not permanently resolve the issue.
• Armoury Crate has been removed/reinstalled without changing the behaviour.
• The problem is isolated to the desktop PC and is reproducible across multiple post-8037 cumulative updates.

Has anyone else seen this behaviour, particularly where only the pinned taskbar right-click/Jump List freezes while the rest of Explorer functions normally? If so, were you able to identify a particular shell extension, driver, or application that conflicts with the newer Windows builds?

This issue is 100% reproducible on my desktop and 100% reversible by rolling back from 8875/8894/8973 to 8037.