If you can connect with ELKRP, you can see what the Installer Code is set to.
I understand that you used a user code for example 1234 and added two digits to the end for the installer code example: 123456. The M1 checks the first four digits for a user code match to arm or disarm. If no match, the next two digits entered are checked. In this case the first 4 digits match and the installer code is never reached.