AirPlay mirror iPad/iPhone to Apple TV

When i airplay mirror from my Ipad 3 or Iphone SE to my Apple TV 3, everything looks fine for about 60 seconds, smooth and great looking, but then the iPad/iphone looses the connection to my Apple TV 3 and the movie stops playing. I just bought a new wireless 5 ghz router but it didn’t solve the issue. My Apple TV is wired/cable cat.6, so I only use wifi to and from the iPad/iPhone. When playing on the iPad/iPhone only there’s no problem. My wifi connection is pretty fast, around 70 Mbps using Speedtest, and my old multimedia player A.C.Ryan “Play On Hd” plays my mkv movie files perfectly - streaming from my synology NAS.
Is this an Infuse issue ?

Which version of iOS are you using on iPhone/iPad?

Are you seeing any trouble when streaming via AirPlay with other apps (YouTube, iTunes, etc…)?