As someone else said, this almost always comes down to the device they’re using. Especially if it’s a Playstation console or a Smart TV (in my experience) as they don’t support x265 codec or have .ass support, or both

Things may have changed then. I owned a Dreamer and everything to do with it was a headache or a nightmare. Neither Cura or Simplfiy supported it and I ended up giving the entire printer to someone else and they had the exact same issues, but i’m glad to hear you had good experiences with yours

Don’t buy Flashforge unless you want to hate your life. They were the first printer I ever bought and unless things have changed they use a proprietary slicer that’s years behind anything else, and they will claim it works with other slicers…until you discover you need to figure out all the settings yourself, including start and end codes