I have an S5, android version 6.0.1.
Whenever I search from Google now, it starts to pull up the results and then immediately appears to be opening another window with the results and then another--all with the same results. It's extremely annoying. If I have used voice to do the search, the google assistant starts to tell me the answer and then is cut off mid-sentence by the second opening of the results.
I haven't been able to get a screen capture of this happening. But I have noticed that when it first starts to happen, I see new text in the search text box. It is something like: "http://www.google.com/?search="search text""
I might not have that exactly right but you get the idea. It's almost like another query happens automatically.
My wife has the same phone and OS and has never had this happen. I have tried reinstalling Google Now. This has no effect. My tablet also has Google Now and this never happens there either.