imac_active binary_sensor remains on after shutdown

**Device model, version and app version**

Model Name: iMac (24" Early 2009)
macOS Version: 10.15.3
App Version: 2021.6 (2021.158)
Safari Version: Version 13.0.5 (15608.5.11) but using Brave (Version 1.25.70 Chromium: 91.0.4472.77 (Official Build) (x86_64))

**Home Assistant Core Version**

core-2021.6.3

**Describe the bug**

binary_sensor.pierres_imac_active remains active when iMac is shutdown.

**To Reproduce**

Shutdown the iMac

**Expected behavior**

binary_sensor.pierres_imac_active should switch to 'off' when iMac is shutdown.

**Screenshots**

Screenshot taken on iPhone after iMac is shutdown.

**Additional context**