Got it. It's clearing the percentage out, so it's making it not blocked. I'm thinking I may have overloaded this screen a little too much. I started with a separate screen for the movement, but then toddled down the path of a 100% mouse restriction is a block. So, I moved it into the same screen as the mouse buttons. I mean, I can make what is in place work, but it may turn out to be a little bit confusing. For instance, selecting, 'Block' and then, 'all but what's listed' *should* allow for the slider to be enabled only if the checkbox is NOT checked (which is what I've fixed it to do). Thanks for your thoroughness
Edit - Going to move the mouse restriction into its own thing, as that would make it easier to understand. The mouse block screen will continue to have a checkbox for full blocking.
Edit 2 - All mouse movement stuff has been moved to its own, simple screen: Restrict Mouse Movement.