If a keybinding is unbound while any keybind is currently selected (such that the "Assign binding to ... or press Escape to cancel" text is shown), the immediate keypress after the unbinding will be bound to the previously selected key despite the UI not visually indicating that the keybinding is still selected.
Test case
Open the keybinding UI.
Left click any keybinding button - such as "Move Forward".
While the text at the bottom of the panel says "Assign binding", right-click the keybinding button. This will clear the binding.
Press any key - despite the "Assign binding" text not showing and no visual indication being given, the key you press will now be assigned to the binding you initially left-clicked.
A video demonstrating these steps is below - the "Move Forward" binding is first left-clicked, then right-clicked to clear the binding, then "S" is pressed. Despite the binding no longer being visually selected, the "S" key gets bound to the "Move Forward" binding.
If a keybinding is unbound while any keybind is currently selected (such that the "Assign binding to ... or press Escape to cancel" text is shown), the immediate keypress after the unbinding will be bound to the previously selected key despite the UI not visually indicating that the keybinding is still selected.
Test case
A video demonstrating these steps is below - the "Move Forward" binding is first left-clicked, then right-clicked to clear the binding, then "S" is pressed. Despite the binding no longer being visually selected, the "S" key gets bound to the "Move Forward" binding.
https://github.com/Stanzilla/WoWUIBugs/assets/287102/9a38a125-0dc4-4812-9a9e-4b23e46ad101