I'm not sure what I'm missing here. I was able to login via facebook on your demo site, but I cannot do so on my client's site. (However, HE was able to.) We are also having problems with Google (I think largely the birthday formatting issue - his store does not require a DOB anyway, so where in the Google process can I comment out something to make it not check for that at all?) Does it affect anything if my store is not in the root but in /catalog? Thanks!
Edit: using 2.3.1, if that makes a difference, and I did do those comment changes as in the instructions.