I don't know but I think it's related to the blink effect (like if the window disappears and reappears). 
Do you want me to send you a video (a GIF on github)? 

2017-07-18 16:41 GMT+02:00 Dan Wilcox <danomatika@gmail.com>:
That should still be working... Maybe single click is grabbing it?

On Jul 18, 2017, at 4:40 PM, Pierre Guillot <guillotpierre6@gmail.com> wrote:

Thank a lot! 
In the help browser of the previous version, double clicking on a folder opens the native OS window of the folder, it was really useful. I'm on MacOS 10.12.5

Cheers,
Pierre