Question Is 65 Minutes Enough for a Connection at SAN?

I'm trying to book a multi-leg trip from PHL to MRY with a stop in SAN. There are flights with AA and AS (AA Codeshare) that have a 65-minute connection time in the evening, but AA won't let me book them together, saying it's not a legal connection. I'm a bit confused because I thought SAN was a relatively small airport. Has anyone tried making a similar connection at SAN? Is 65 minutes really not enough, or is there something else I'm missing? Would love to hear if anyone has insights or experiences with tight connections at SAN.