please provide the link to the video.
Often quality and speed is based on YOUR internet connection, i.e. a video you can only see in 360p I can possibly see in 1080p because I have 150MB download internet connection and you have a 5Mb connection.
also here is a wbe page that explains how to ensure the video you upload remains in 1080p or 4K when you upload them :https://www.youtube.com/watch?v=_VVQwgLIYHw