So first let me mention I had a similar issue a few months ago. Then we were getting alarms even when the system was set to disarmed but the time stamps made no sense and some parts of the rules never ran. Usually it would turn on most of the lights but miss one. I had gotten some suggestions but never got to try any since the problem went away.
For the last few months the HSM has been pretty stable with some strange behavior but nothing too terrible. For instance sometimes arrival lights don't turn on but HSM was disarmed.
Now what we are getting is frequent false alarms. I can see time stamps that the wife was disarming at keypad (Iris gen2) and it would still go off. I confirmed she was waiting till the light on the keypad changed so really I had no idea why it started doing this again. A couple days later I thought we may have found the problem when with the alarm going off the keypad started strobing. When I looked at the keypad after work (batteries removed) I found it was still driving but batteries were low. After replacement the keypad seemed normal but false alarms continued.
So next I added a button in our bedroom to disarm the system. I figured this would give the system more time to actually acknowledge it was disarmed before she opened the door. This was working until this morning, when she got to the door she checked the keypad and it said Off like normal so she went out. Then the alarm went off. But based on time stamps I can't figure out why. In the screenshots below you can see the system was disarmed but it still went off. The times seem to make sense between button presses, door opening and alarm trigger but why go off? Based on this being such a step change I am wondering if is is caused by the updated hub software...thoughts?