Follow-up!
I bought a second pair from Costco to compare the clasps side by side. The new pair wasn't perfect either but after manually pushing the post downward ever so slightly, they close securely and I'm a happy gal!
And of course the itch continues. I'm now eyeing a pair of oval pavé hoops with a 1.5" drop. Up until now I haven't preferred pavé mainly because I feel they look a bit "costumey" or perhaps because I've seen so many faux ones that look nice enough that it makes me question why buy real.
I definitely prefer the whole stone look over pavé but now that I have a few whole stone hoops, does it make sense to buy pavé?