Why does the Quick Settings panel sometimes refuse to open on Windows 11?

Why does the Quick Settings panel on my Windows 11 PC occasionally refuse to open when I click the network, volume, or battery icons in the taskbar, and why does it sometimes open as a completely blank window with no toggles? It works fine most of the time, but every few days it either ignores my clicks or shows an empty panel until I restart Explorer or reboot.

Could this be caused by a corrupted shell experience, a broken system tray process, or something that a recent update changed? And is there a way to fix it without resetting the whole taskbar or reinstalling Windows?