Youtube Premium is so dodgy. It's already expense and even if you get it, they will default to a miserable 480p on Mobile, while you have 1080p60fps available.

You can change it manually, but it's a defeat of the entire purpose..they intentionally removed the setting to apply the max. quality available to all videos you watch, while already charging you a monthly subscription for the goddamn premium. What a bunch of goo(gl)ns