Ah. Unfortunately, that’s not what I see. I’m guessing this is a markdown issue. I feel like I’ve seen lack of markdown support being mentioned as an issue with lemmy on mobile. Here is what I see:
https://files.catbox.moe/c1nrqz.png
So… I guess you could manually number them for idiots like me… or just wait for markdown support to work properly.
A workaround for you: upvote twice (ie upvote and remove the upvote) to get the post marked as read.