Triggers using the state "is not Normal" condition not working correctly

Hi there, 

I was working on a drag drop exercise in which I wanted to disable the Submit button until all the options had been placed however I ran into an issue when using a trigger with the when state is not Normal condition. The trigger simply didn't work even though all the options had either the Drop Correct or Drop Incorrect state i.e. the state was not Normal. 

I have got the interaction working by instead enabling the Submit button when at least one of the options is either Drop Correct or Drop Incorrect however this does mean that the answer can be submitted even when only one option has been placed. Anytime I tried using the "not Normal" condition for a single option or for multiple objects e.g. "if none of the objects is Normal" it would not work correctly. So although this specific interaction is fixed I'm curious to know if there is a reason why Storyline does not register the object as "not Normal" when it is in a Drop Correct or Drop Incorrect state.