There is a chance this is actually a very simple issue given that I don't understand much about CSS, but given that I did not find information about this I figured that maybe this was worth asking here. Still, I apologize if the answer is in an easily accessible place I somehow missed.

I recently got custom CSS support enabled for my account in order to polish up the page for a game I plan on releasing soon-ish. My original plan was to use CSS to host gifs that were too big to be uploaded normally from another site to add to the description, but it turns out the gifs are so big that trying to load them like that resulted in them playing extremely slowly if at all.

I eventually found a solution which is to have a mute mp4 file play on loop, which would give the same effect while being small enough to actually load. I tested the code in other websites and it worked, and it even worked on the "edit game" page without any problems, as in the video was playing like a gif inside of the description editor.

However, on the game's actual page it doesn't load. By using the google chrome "developer tools" to see the code I noticed that not only the proportions specifications weren't there but also that the source was in quotes and greyed out, which I assume means it isn't being read for some reason.

For reference here is the code in question, with the link to the video being swapped out

<video width="320" height="240" autoplay loop muted>

 <source src="insert mp4 link here" type="video/mp4">

</video>

I would like to understand what is happening, as in if there is a problem with my code/the way I am approaching this or if it's something like itch.io blocking videos from running through CSS.