@dellalibera Hi there, thank you for reaching out.
One thing to note is that the Web Stories plugin has a video optimization feature enabled by default. This feature automatically optimizes and compresses videos that are uploaded to the Media Library within the Web Stories Editor.
There are ways to store media content outside of WordPress but still be able to use it in your Web Stories and other WordPress content types through the Media Library. This is commonly called “offloading,” and you can find more information about it via Google search. Essentially, offloading allows you to use the WordPress Media Library as usual, but actually store the media on a different server.
Which CDN/ offloading service are you using?