Can't play music/view pics or video on any other device cast from phone via cast dlna etc

[AC Question]

I use to be able to load either my music player or album etc and press a screen option in the top right and it would find either my TV or xbox one and start playing through which ever I chose. After I received this system update too android 7.0 the icon is no longer showing in any app cast won't find my devices. But you tube app can and plays fine. I'm using Sony Xperia z5. Is there a fix have they removed the features? Can I revert back too the older android which in my opinion is much better. I had better battery life by miles for 1 and the os runs very slowly.