I have just started my DB. about 5k hands. I am learning how to filter and look at the data.
I have AA 23 times and a 3 in the Blind

when I filter and check NOT A Blind
AA shows 1 time... In fact out of 5k hands I only have 18 hands total????

I am able to filter for specific hands and check NOT A Blind, it works fine. But when I try to do all hands It will not work?

check the prefs page - you have all hands from all sites since the beginning of the DB selected? (under all aliases?)

Could it be that you have mistakenly double-clicked on one particular session in the sessions list? Maybe check that list and make sure one of them is not in bold. If that's the case, it's going to filter out all hands not in that session. AFAICR, anyhow.