Video quality in highlights

Hey everyone!

I'm trying to make videos and upload them to YT, but so far I am really disappointed in the quality of the video image. I'm making highlights of the replays through the client and the quality sucks. Is there some kind of option that allows me to make it have better quality?

Look at this video for example: https://www.youtube.com/watch?v=JuBLHFdh4i0

I don't know why, but the quality is really bad and I'd like to change it so it will be better. But it's the same even when I go to my highlights tab on the client. Only when I play the full replay of the game does it look okay. Do you have any advice in how to make it better?