I’m on OSX with the latest Chrome. Like I mentioned above - I only get the Discourse dialogue on 1 in 2 threads when pressing CMD + F. The solution suggested by @vibrocil works well though, so I can live with that for now.
It is odd that you’re not getting the dialogue is using Chrome though? Could you open for instance this thread and try there? For me it happens every time I use the keyboard. From the menu, I always get the browser feature. This happens on Win10/Chrome and OSX/Safari also.