I just noticed the same issue on seeing your own posts. Other apps like Mlem, Memmy and Voyager seem to have found a fix for this, because in those apps I can both see my saved posts as well as my own posts, even though I’ve already read them.

Do comments make read posts reappear as unread? It seems to me that post that have activity should reappear based on some preference. 

I like this idea, but it should also bookmark any post you reply to or create. 

And continuing my feedback on this topic, I also think you need to be able to customize per feed if you want to hide or not hide read posts