For now can you assign the pir to a different area and key switch monitor only.
This way it won’t trigger alarms sounder but you will get a notification when it’s activated and then you can look at how many times it activates.
what you are looking for is how many times does it activate and how close the activations are, so time stamps day hh:mm:ss are very important.
You want to do it for some time so you can get a good idea of what’s happening.
Cats for example won’t move around all day and unlikely to react to someone outside the property like a dog would.