Identificaciones de jgw_atx

Spotted what looked like a classic black widow web. Upon looking for the spider, I discovered this small spider in the web, upside down. Markings of underside were unusual. Coaxed it out for a look & assumed it was a male juvenile black widow with slightly unusual markings. Most images in iNat are suggesting filmy dome spider (Neriene radiata). Because I've never seen one of these or heard of them, hesitant to positively identify. Simply putting this in the general "spider" category in hopes someone with more knowledge can identify better.

This juvenile Argiope argentata appears to be almost exactly the same age as the female I just posted, located about 3 meters away at the other end of the window structure. They were identical in appearance, but over the intervening time, changes have emerged. Now I think it is evident that one is male and the other female.