Apple Music playlist issues on Apple TV4

I have two issues with Apple Music on the new Apple TV, both related to my own, existing playlists. Firstly, there doesn't seem to be a way to shuffle the tracks in a playlist. Secondly, you cannot see (or, therefore, play) more than the first 250 tracks in any playlist. You can shuffle Apple curated playlists. I am also having trouble with buffering when playing some songs; some songs play fine, others continually stall (no obvious issues with my broadband). With these, and one or two other issues, I'm rapidly coming to the conclusion that this new box is far from ready for sale...