It looks like a recent update might have change the moderation queue detail page so that the editor on that screen is now very small on shorter posts when in raw markdown mode, and it can’t be expanded. (Firefox 143.0.1 on MacOS Sequoia 15.6.1)
Edit: actually, I’m not sure about this. I’ve already approved everything for this morning though and can’t double check right away. Try switching back and forth between WYSIWYG and raw markdown, and the preview doesn’t disappear for the WYSIWYG so there are two versions on the page. I think the monospace font also disappeared in the raw markdown editor, so I’m looking into that now.