Thank you for stumbling upon a way to make link posts work for me on mobile after landing on them through an RSS reader.
I think link posts are broken for everyone currently, as far as I can tell. Have a bonus link to the follow up blog
Huh, for some reason this wasn't actually a link post. I made it a link post now. Was there any problem in adding a link? (I.e. you have to click the grey button at the top that says "Create Link post" and then post the URL in the text field that shows up)
I did that. But it ended up in the state you found it in. I saw someone else complaining about link posts (so I thought it was a known problem)