It's probably because the images for the volume control sliders are also not in the right place since the text has gone weird as well >.< It seems like no matter what I do with the scaling UI settings in Unity, they never scale properly for everyone :( They either end up making stuff completely disappear off the screen or putting it so it's still on the screen but in a really weird place T_T and I have no idea how to fix that, especially on a mac where I can't even test because I don't own one or know anyone nearby who does >.<
So yeah, I'm sorry about that but I'm unlikely to be able to fix it :( It's so frustrating when I've worked hard on stuff to get it all working perfectly on my own computer only to discover that it's completely or partially fucked up for other people >.< I guess that's where having a proper team helps, haha. But since I'm just a solo dev doing all this as a hobby, I'm pretty much useless when someone runs into a problem like this.