Releasing Super key doesn't close application switcher when Sticky Keys is on
GNOME Shell 3.34.3 on Ubuntu 19.10 (but I think this issue also applies to GNOME 3.36 on Ubuntu 20.04):
Enable the Sticky Keys feature (Settings -> Universal Access -> Typing Assist (AccessX) -> Sticky Keys)
Double-tap the Super key. This causes Sticky Keys to simulate that you're holding down Super until you tap Super for a third time to release it
Tap Tab. This'll open the Application Switcher and keep it open, since Sticky Keys is holding down Super for you
Use Tab, `, and the arrow keys to selection an app or window to change to
Tap Super again to make Sticky Keys release it
Expected behaviour: releasing Super should exit the application switcher and focus the app or window that you had selected, just as it would do if you were holding down Super without Sticky Keys.
Actual behaviour: nothing happens when you release Super. The next time you press anything though (e.g. Tab, or an arrow key), then the application switcher will exit. Sometimes it will exit and focus the selected window, sometimes not (it seems to depend on which key you press next after releasing Super).
This definitely seems like buggy or unintended behaviour because it's confusing and inconsistent. If it's not a bug though, then consider this a feature request: exiting the application switcher when I hit Super for the third time to have Sticky Keys release it, would be fewer clicks and easier to remember than the current behavior.