No they are not new, I have been experiencing them for a long time now, as I said intermittently, but it’s been happening all throughout the issue with the 5.1 mapping problem.
On another note, I have just realised I cannot play movies with Atmos tracks on 1080p h264 files now. The files will default to the 2nd audio track, or if there is none, skip to the next movie.
HEVC 2160p Atmos is fine. And DTS-HD audio is fine too.