It sounds like you might be having some overlapping issues. Since the "error on post" thing started happening, I've noticed that new posts won't show up in the default "hot" ordering. I assume that this is a sorting bug and they show up at the bottom of it. This was also happening when I first joined kbin, although the error page on post thing wasn't happening then.
The workaround seems to be to go back to the magazine's main page after posting, and sort by "new". Your post should then show up at the top. Upvote your own post, and then when you go back to the default "hot" ordering it should show up at or near the top, as normal.
Hopefully this fixes at least one of those issues. Good luck with everything.
What seems to be happening is that your post is being sorted incorrectly in the default "hot" view. This was also happening when I first joined kbin, albeit without the error page when posting. Your "logged out" image shows the "newest" sort order, however.
The workaround is to immediately go back to the magazine's main page after posting and switch to the "newest" sort order. Your post should then show up at the top. Upvote your own post, and then it should appear correctly at or near the top of the default "hot" view.