This because the passcode that is being entered falls within the Duress of another passcode, even though Duress is not being used, or a Duress type 1 has been selected. There is a safeguard built into the panel that does not let passcodes that fall within 2 of the code be entered. This is in case a Duress Type 2 is selected later. Pleases follow these guidelines when programming passcodes .
The programmer does not allow you to enter any passcode number that could conflict with a Duress passcode. This rule applies even if duress is disabled.
For example, once a passcode of 654321 is entered, 654322, 654323, 654320, and 654319 cannot be entered.
