Finally got a search result. It was for section 413, lol. I didn't wait this long (waited until the good seats went on sale) to only get that kind of a section.
Ok, I was 1 min away from buying them on the aftermarket.
When I went back to the BNP Paribas website.
This time, on the seat map, "Lower Level" was selectable, and in blue. Previously it had been grayed out.
And I was able to find seats in a section I wanted. So I bought them at face value, and got exactly what I wanted.
So lesson learned. Just because tickets go on sale at 10am, it doesn't mean the online map will be fully functional and allow others to select the newly available seats. Sometimes it takes 70-75 minutes for that map feature to work.
So, don't get frustrated if the seat map isn't working right away, and all of the BNP Paribas phone numbers are giving the busy signal.