I don't know if you have a problem here, as my truck does the same thing. On my '50 you cannot unlock the passenger if the interior door handle has locked and my drivers won't close if locked from inside handle. If I am driving with someone, I have them lock the driver's from the inside before exiting and then I lock the passenger's side from outside without locking the inside handle. If I am alone, I either lock the driver's from inside and slide over, or reach in from the passenger side and lock the driver's, then the passenger's is locked with the key from the outside only.
