After upgrading to the new YouTube app, 4K videos only play at 1440p. With the old version they played at 2160p. The PS4 YouTube app plays 4K videos at 4K, does any one else have this issue? I went back to 1.3 as there is no practical difference. And the difference between 2160 and 1440 is noticeable. I have a Sony XE9305.
Same problem, very few videos stay 4K now...