THANK YOU FOR THE RESPONSES!
I don't know, I really think I got the moody VLC. I have some pretty suspect taste in videos, so maybe VLC finally had enough and decided to fight back.
Before this issue, I had never been in the preferences, so not sure what I'm looking for.
Makes sense when I read that selecting NEXT in the menu just tells it to go to that one now and not a stuck setting. I've actually never gone into the menu until this issue started happening. I always just played a videos by dragging groups of videos in, and it used to automatically go the one below it. Or I would open the screen and drag them in one at a time until I got the playback list.
Is there a way to make it play them sequentially as a default?