How does HomeKit detect my family member leaves home automation iPhone.

1. I try to set up automation to turn off the lights and air conditioning in the leaving room when last family member leaves. However, it doesn't work.
2. I change the scenario to turn off the lights and air conditioning when I leave. it works.
3. I make sure the following settings of her iPhone 13 is done.

• • Settings > Privacy > Location Services > On
  • Settings > Privacy > Location Services > System Services > Homekit > On
  • Settings > Privacy > Location Services > System Services > Find My iPhone > On
  • Settings > Privacy > Location Services > System Services > Significant Locations > On
  • Her apple IP is added to my HomeKit already.

Could you please provide your experience to solve this problem? Please me know if any questions. Tks.