So, uh, I think Catalina 10.15.4 Broke SSH?
I was completely at my wit’s end and feeling like I had lost my mind until about a half hour ago. And I don’t know what difference connecting via a hostname versus an IP address would make when specifically using a non-standard port above a certain threshold. I’m not even going to go into it. I don’t want to end up on Hacker News again bitching about Catalina. I just hope I’ve stuffed this post with enough keywords so that anyone else searching on Google might come across the answer.