There, third time’s the charm (or 10th, more accurately, since lemmy.world is shitting the bed right now).

I think I figured out what was going on, too. The app I use was automatically re-parsing spoiler formatting into its own syntax, but then was erroneously applying that same syntax to text when attempting to view source. So even the example you posted looked different to me when viewed in app versus on the actual site. I made the edit from the site this time and I think that should be good now.