I found it very difficult to redock a window that I undocked after clicking on the pin. Had to read the manual, which is hard to do in the middle of an event.

So I am writing it here, to help people.

To undock, click the Pin.
To redock, click the minimise window button.

I don't know what to do if you want to leave it undocked and minimised.
I don't know what the developers were thinking. Why use a standard windows control button, instead of just toggling the pin.