If a ui button is clicked, you have to move the mouse off and click to revert to normal color or animation

Questions & Answers
1

what fixes this?

2

Add these lines to Start function of any script in your scene, or create a new script

 void Start() {
		Button[] allButton = FindObjectsOfType<Button>();
		foreach (Button button in allButton) {
			button.onClick.AddListener(delegate {
				UnityEngine.EventSystems.EventSystem.current.SetSelectedGameObject(null, null);
			});
		}
    }