Except facebook web always show me 1080p on mobile data connection. I have reported many times but I guess they don't care about user feedback. If I select 480p on youtube, It will never show me 1080p, unless I switch back to 1080p. On facebook, every video is by default 1080p. Even if I don't watch video, scrolling news feed also pre-load 1080p. This is a huge problem with limited mobile data plan.