Second addition of device tracker because of others consider_home

Hi,
I try to add an second device tracker (PING), for others consider_home

this is my config:

# IP Device Tracker
- platform: ping
  interval_seconds: 1
  consider_home: 0:15:00
  hosts:
    iphone 1: 192.168.1.201
    iphone 2: 192.168.1.202
- platform: ping
  interval_seconds: 1
  consider_home: 0:1:00
  hosts:
    desktop: 192.168.1.60

The desktop can be found, but then I switch the desktop off and it is still online in HomeAssistant for 15 minutes.

What am I doing wrong?