Background Video not showing up


I am new to Webflow and love it so far but get confused easily. One thing I could not solve on a project, my first client project, is how to make a background video in the header upload and display correctly.

It’s a 720p, 3 second mp4 (2.5mb in size) so it should not be a problem per se.

However, it takes forever to transcode, then it says «unknown size» and shows no preview in the settings window and the video never shows up.

Have tried with many different exports from iMovie to Premiere in mp4 and mov.

Right now I use a GIF to show instead but it’s half the quality and twice the size of the video.

Does anyone of you wizards now what I might be doing wrong? Here’s a link to the project.