2007 mercury mariner, oem alarm

Wonder if this issue had come up. I installed a remote starter for a customer and upon completion of install, oem alarm doesn't work properly. I hooked into correct arm and disarm wires testing with key in driver door cylinder. The customer bought a Bulldog 2 way remote starter and a transponder universal bypass. I put key into box and buried into under dash. Could this key inside vehicle be responsible for the alarm not working? Lock door and shut door, parking lights flash, indicating alarm has been activated. I manually open door through open window and alarm doesn't sound. I use factory remote and double lock with the same result. Has anyone else had experience with this?

I accessed wires in the drivers kick. A pink/white lock unlock single wire set up with 1k ohm resistor. blue/ lt. green disarm WHITE/ purple arm I set the system to single pulse. If you turn the key in the cylinder it only sends one pulse so that should have been fine. I even used factory remote with similar results.

Are you waiting for the system to arm up after locking? Give it a minute or so before opening the door and see what happens.