I have a strange bug on windows, and seems to be also on mac but here it is much more rare. Anyway its not simple to reproduce it so i don't have i screencast but i will explain at my best the situation.
This bug regards the click event on the editor: when i click an element i see on it the feedback of the selection, i see it selected on the outline view and i can move or resize it. But the properties view is not updated with the current selection, it keep the property of the previous selected element (so if i change something in the property i'm not changing the properties of the element that i see selected, but the one that was selected before). And it dosen't take only the property view, but also common operetions like delete, copy and paste.
But if i select the element from the outline there aren't problem, so it happen only when i select it from the editor.
I've see that this happen often when i save a big document, but not everytime. The only way to return to the standard behavior of the selection is to close the document and reopen it (it isn't necessesary to close also JSS).
There aren't exception or error so i can't say why this happen.