Lars,
Thanks for having them take a look at it.
Concerning the sensor, to be honest, I don't get how it's intended that it sends a motion/no motion signal at the same time. It detects motion, but sends it doesn't.
When I activate the notification for this sensor, I always get 2 notifications at once, 1 for motion detected, 1 for motion stopped. That can't be how it's supposed to be, right?
Also, in the rules UI, you can use 'No motion' as a condition, but the way the sensor is working, I don't see how you would be able to use that...