Woooow... I spent hours trying to understand what I was doing wrong there. I made a small .CAPX too and was about to post the bug when I saw your post with the flaming icon, and I was shocked to read a title I was about to write.
So yes, it's a very annoying bug and I have made a small example too: https://www88.zippyshare.com/v/5KTgQmw3/file.html
Basically, you have two identical characters, two zones and a blue square.
If selected character is moving over Zone 1 or 2, hide Blue square
If selected character is NOT moving over Zone 1 or 2, then show Blue square.
(Move them with basic keyboard arrows)
And here the bug is that, even if the selected character moves, while the second character is over a zone, the blue square is still displayed while it should be hidden.
I know it's not something you can understand right away in 5 seconds, but after playing with it for a few minutes you understand that it's not reacting the way it's supposed to.
I know you guys are working on C3 and the progress you've made so far is amazing, but I didn't think such a core mechanism wouldn't act as intended.
[EDIT] : Indeed, the "simplest" workaround right now is to avoid using "OR" blocks combined with "Pick ...". The annoying thing is that it makes you multiply events unnecessarily...