User blog comment:MisterWoodhouse/The first migrations to the Unified Community Platform/@comment-25999669-20201222110638/@comment-1038387-20201222160832

That tabber issue is a bug, I recall. Though I've seen it mentioned an additional line break changes that. As I don't use tabbers I haven't checked that.

Line spacing in general is a bit different in UCP, both in content and on Special Pages. Usually that's not a problem except getting used to it. I'm not sure what high writing standards have to do with spacing or images though.

Also, keep in mind that to you this might seem broken, but to Fandom, it's not. Everything works, nothing is broken or overlapping, it's just that your design choices don't properly align. If they even consider the line spacing a bug, it's unlikely to be a priority. If you approach them for a solution, they'll probably tell you to work around it. You can look into changing it via css.