Alarm doesn't disarm properly

[Rowbotronics]

When the alarm is armed scanning a key doesn't seem to disarm it the first time. The pre-alarm starts playing and the key needs to be scanned again to disable it.

2016-August-18 11:46:28 message 01 Front door: door closed
2016-August-18 11:46:27 error Alarm Decoder: alarm-armed-away
2016-August-18 11:46:20 message 01 Front door: door opened
2016-August-18 11:46:19 unlock 01 Front door Paul Herrington 04fcc9daed4480
2016-August-18 11:46:19 message Alarm Decoder: Sending disarm
2016-August-18 11:33:15 message Super Serial connected!
2016-August-18 11:33:14 message Super Serial disconnected
2016-August-18 11:33:13 error Super serial watchdog activated