Troubles rendering html with pandoc

I don’t know if this is a gitea problem or a pandoc problem, but I’m starting here.

I have html pages in some of my repos that I’d like rendered within gitea. I understand the risks in doing this, but my instance of gitea is only used internally by myself, and I’m the one generating the html.

Here is an example html file:

If you open that in a browser, you’ll find it has some tables and some images. The tables aren’t being displayed properly, and the images aren’t being displayed at all.

I’m using RENDER_COMMAND = "pandoc --from html --to html5 --self-contained --template /home/gitea/basic.html"
to attempt to render the page