Fantastic, sony have messed this up for us all as well now. If it wasn't bad enough that external storage devices mounted as internal storage constantly unmount themselves or go read only, resulting in apps going missing, tv programs not being recorded or the tv crashing when trying to download new apps, they've now ruined the built in chromecast cast.
So, here's my experience so far. We have 3 phones in our household. My phone connects okay, my boys phone connects sometimes, when it wants to and my Mrs phone is generally okay as well.
The main problem that I am experiencing is when trying to connect multiple devices (one of chromecasts best features) originally, when I had guests round for a house party, I could start a playlist on my phone, others could then connect with their phones and add songs to the same playlist. Unfortunately now, if someone else connects their device, the previous device, along with the playlist gets kicked off and more often than not, it gets stuck on the youtube title screen. This happened at the last party I hosted so I switched to Spotify hoping that would solve the issue, unfortunately, it did not.
The only way I can get it working again is if I go into apps/chromecast built in and then unistall updates, clear data, force close and then restart the tv. This sort of fixes it temporarily, although it still seems buggy. For instance, connecting another device whilst one is already playing, results in the youtube title screen popping up and the current playlist pausing but then it will start to play again and the playlist will still be intact.
Unfortunately the chromecast built in app, automatically updates again causing everything to stop working again and there is no way to turn off these updates. I find the whole situation so frustrating and I've just about had enough of sony!!
