JC registration/pedigree help?

[ne to socal]

I'm somewhat active on a FB group for Rockingham Park, and members post lots of win pictures there.

So many of the horses' names don';t show up on Equibase or pedigreequery or even at the JC naming registry.

These were legit TBs as far as I can tell...sires are familiar (if not spectacular).

Why could this be?