Youtube hq feature won't work

[Frederick930]

hi guys, i'm new here and this is my first post
i have a problem with the youtube mobile site (m.youtube.com, not the app)
there is the hq feature for videos but i seem to can't get it to work, when im using the youtube app, the video randomly choses hq or not, sometimes it uses high quality and somtimes not which makes it annoying
is there a way to fix this?