Embeded videos are stuck


Recently I started adding embeded videos on my website and I have the following issues that I would love to solve:

  1. Sometimes they are stuck on the first frame (some, or all).
  2. On mobile they are not playing at all.

Videos are located in the following sections:

  1. The Solution
  2. Final Designs


<video width=100% height=100% mute autoplay loop>
 <source src="linktothevideo" type="video/mp4">

Does anybody know how to fix it? It’s especially visible on mobile.
Videos are hosted on Dropbox.

Here is my public link: **https://www.dannysvibe.com/saucey-live-activity-design (temporary password: helpneeded