HSM Bypassed sensor triggers alarm

I'm using HE and a Konnected Pro board for home security. The contact sensor for my Master window is configured to be bypassed if open when HSM is set to Night. It usually works fine, but a few times lately in the middle of the night, HSM triggered an alarm from this sensor. The attached log shows the contact open several times but the alarm was only triggered at 4:35am. I don't understand what made the alarm go off when it did. Any ideas would be appreciated.