I have a rule like this:
if iphone is absent and pir is absent for 15 minutes then execute "curl admin:password@localhost/api/device/thuis/changeContactTo?contact=true >/dev/null 2>&1"
So when my phone is not pingable and the pir is absent for 15 minutes it sets the dummy contact to closed (no one home). But sometimes is randomly changes to open and to close again. like this evening:
19:53:15 home closed
19:53:15 home opened
very strange, and my phone was not absent at that time. and the pir was already absent for more than 15 minutes.