Slow downloads when Jellyfin behind Nginx reverse proxy

Hi everyone, I have set up Jellyfin on a Ubuntu 20.04.1. It mostly works really well and when I download a movie from Jellyfin , I get around 500 mbit in speed. When I instead connect to the reverse proxy(with https) and download the same movie, the speed is limited to approximately 60-70 mbit. I have set up nginx according to the instructions at https://jellyfin.org/docs/general/networking/nginx.html for a subdomain set up. I don’t see any other issues besides the speed limit. I haven’t set up any of the “Extra Nginx Configurations”.

Does anyone have any idea what could causing this?

Best regards