2000 Chevrolet K3500 Electric Door locks working properly?

Hi everyone.

I recently purchased a 2000 Chevrolet K3500. The electric door locks did not work, so the dealership replaced the actuators (all 4 they say).

The first time that I press "unlock" on the keyless entry "remote", it only unlocks the driver's door. If I press it again, it unlocks the rest. Is this how it's supposed to work?

Thank you VERY much for your input.

Misty