The alternative visualisation functionality has only just been added to Sense in the June 2017 release. I've not had a chance to try it out myself yet. As such, there could be glitches with it.
I would recommend that you put your expressions into simple Text objects to see the output from those changing.
Note that GetSelectedCount returns 0 if nothing is selecting (i.e. everything is selected).
You will be much better off using GetPossibleCount,
GetPossibleCount(StateArea) = 1
GetPossibleCount(StateArea) <> 1
You don't need to add the IF statements returning 0 or 1, the expression will return the correct value anyway. Also, I would always go for the same expression for a straight toggle, just with = and <> in there (rather than = and > as you have, as this does not take into account < 0 or null()).
Hope that helps. It's good to see this functionality finally available and being used in Sense.
That is sounding like it could be a bug then. You could try a simpler expression, just to test, perhaps have a variable and set it to 0 / 1 with a button (you will need an extension for this, see https://www.quickintelligence.co.uk/toggle-buttons-qlik-sense/ ).
If the issue still occurs with a very simple toggle then I would suggest reporting it as a bug via the Sense June 2017 Technical Preview forum.