I’m not sure if this is the case, but the ST sensors are not that reliable. There has been a lot of talk about the “newer” motion sensors being slower than old.
The newest generation seems to be slower than previous versions. @whoismoses has a video of this issue:
[SmartSense vs SmartThing Motion Sensor Performance]
That said, to get the quickest response rate out of any zigbee motion sensor, try the following:
One) heal the zigbee network to make sure you’re getting maximum efficiency out of what you have. For zigbee, this is easy. Just take the hub off of power for at least 15 minutes (including removing batteries, if any) while leaving the other zigbee devices on power. This is long enough for all the other devices to go into “panic mode” because they can’t find the hub. After you power the hub up again, all the devices will rebuild their neighbor tables, finding the most efficient route. It can tak…