Win+Shift+Up maximizes the active window vertically while maintaining its width.
Win+Shift+Down used to do the reverse, that is, restore the previous vertical dimensions.
The latter stopped working in Windows 10 20H2 (maybe already in 2004). Instead, Win+Shift+Down now always minimizes the window like Win+Down, as if ignoring the Shift modifier. I tested this on several independent installations and also in Safe Mode.
EDIT: I also checked with Spy++. The key messages go to the respective active window (as expected), except for VK_DOWN which doesn't appear. Instead a WM_SYSCOMMAND with SC_MINIMIZE is received. There are no WM_HOTKEY messages.
Is there some way to restore the previous behavior?
Is there some other keyboard shortcut to undo the vertical maximization?