That is interesting, and does slightly make me wonder if somehow me trying to just Dupont-wire it directly into my Uno somehow was problematic? I wasn't initially even trying to do my ultimate project, I was originally just trying to verify my soldering work on the header pins was solid before soldering the rest (did NOT expect the rabbit hole this thread has become). I didn't bother with a breadboard because I wasn't really trying to accomplish much. I'm absolutely willing to bring a breadboard into the mix now.
Like I was telling sonofcy above, giving this a whirl will have to wait until I am home with some time and spoons, but I'm absolutely going to see if this works out better.
If it doesn't, I might just solder together one more sensor and see if the first one really was just a defective fluke.