Hello,
Please point me in the right direction if this is not the appropriate place for this post. I did a search and did not see another post in regard to this. After updating to public beta 6, I have discovered a bug with Airplay connecting to an AppleTV to use as an extended monitor. It will connect and display, but when you select "internal speakers" instead of the auto selected tv speaker output, Airplay stops working and you have to manually stop Airplay and connect again. I have not had this issue previously. I have tried this on an AppleTV with and without the tvOS beta and it exhibits the same behavior. I have not found a way around this issue and it happens 100% of the time. Thanks in advance.