Add door sensor

I've added a door sensor before, but something is different this time. I have an Ademco Lynxr-CR as it shows on the circuit board. Trying to add a sensor that I bought on Amazon, a 5816VMWH. When going through the steps the system will not take the serial number shown on the outside of the device. I have tried entering manually and using the 4 transmissions 5 seconds apart method. When out of programming if I pull the magnet away from the sensor the alarm announces "disarmed, not ready to arm"