apple tv AirPlay problem with Beamer

Apple TV 4, 10.2

iMac 5k 10.12.4

When I play movies on my TV I usually use Beamer to send them to the TV as AirPlay often has little "hickups".

Since yesterday Beamer does no longer work. I get the following error message:

"Apple TV" requires device verification.

Device verification is not supported. In the Apple TV settings go to AirPlay, Security and turn “Require Device Verification” off.

My Apple TV 4 does not have that menu item. I only have "Security" under Access Control. Security itself does not have a submenu where I could turn off device verification.

How come my menu is different from what I found even on official Apple sites and what should I do to have a complete menu and/or solve the problem?

Thanks.