I just got back from El Rey and both Bank ATMS gave the same message for a $500 withdrawal request. They said something to the effect that either your bank is unavailable or you have withdrawn more than your daily limit.
Since my daily limit is $500 as confirmed by my credit union, that would imply the bank was not online. Before leaving, I decided to ask for $300 and received it.
Personally, I don’t trust. Clave.