airdroid does not disconnect when power button pressed

When I am done with the web interface, I click the power button top right and nothing happens. I wait a few minutes and click it again and nothing happens.I have to exit the window and go to the phone and disconnect from there.
This happens every time.
Why is that? The power button should work.

Hi xeroy,
If you want to stop the connection of your device and computer, you just need to close web.airdroid.com.

By tap the power button of your device won't stop the connection of your device and computer.