I found what I was looking for in the database. In rp_categories, it's the column named sortorder. Changing that to 8 did what I wanted. I did not see a way to do that in the edit categories admin section.
That's not something new in there that didn't take when I upgraded, is it? I see where I can order the display of the top level categories. I see where I can click on "sort subcats" and order the display of the subcats but no way to order the contents of the subcats themselves, which is what I wanted to do.
I was only able to find the value stored in rp_categories in the database. So I managed to change it but wondered if there was an easier way to change it that I didn't find.