Forums for other home automation platforms have reported that this is a common issue with this device.
If there is something in the environment which is not a person, like a fan, it will not be detected as a person. That’s the good news.
But if a person then walks into the detection area, turning on “presence detected,“ when the person leaves, the fan or other non-person event may be enough to prevent the “human present“ state from clearing.
This appears to be what the “reset no presence” option is for. It clears the “human present “state.
As I mentioned, this seems to be a common issue with this device, regardless of the hub being used. 