What would possibly explain this? What about these events would require a full siren event from the panel?
That “Pending alarm” event means that the sensor sent a fire alarm signal to the panel. Disarming the panel while the sensor is still actively reporting an alarm will typically result in a subsequent alarm event at the panel, this is expected. Disarm does not dismiss future triggers of that sensor.
When working on sensors, especially fire and CO detectors, it is recommended to place the account on test mode in our system manager to avoid accidental dispatch. Accidental activation is possible depending on the sensor, where the sensor is placed, accidentally hitting the test button, etc.
The sensor will report a resolution to the trouble condition/tamper when returned to its mount.
For the price point of a “monitored” sensor I would expect it to tell me something about the battery before it’s dead enough to start beeping.
A low battery event will coincide with the sensor itself beeping and flashing its LED to indicate the condition. This is so even if it is not connected to a panel, the sensor warns the user of a low battery. This is expected and I believe a requirement by fire code.
I have another IQ Smoke that just randomly false alarms for no findable cause
Common causes of false alarms are described in the link below. Where was this one installed?
How many alarms occurred, and can you confirm the rough date when this was active on the system?