Video background drops quality when uploaded

Hi ! I am trying to have a video as a background on my page but when I upload it the quality drops quite a bit and it doesn't look good... If I try using the link from Vimeo it asks me to try later...any suggestions??

Website: https://walrus-gold-b9b5.squarespace.com/

Password: supernothing

Thank you!

Here is the original video and how it should look: 

Background videos prioritise loading speed, do it's not unusual for their quality to be poorer than desired dependant on your connection. There's not a lot you can do, but I suggest you persist with testing it via Vimeo or YouTube to see if that works better for you.