Assigned commands to the properties EnterFullScreenCommand or ExitFullScreenCommand don't get executed

[jmcortorreal]

Hi, thanks for the repository it has been great finding it, however I am a little stuck at assigning commands to the properties EnterFullScreenCommand or ExitFullScreenCommand, because my assigned commands are not called at all, it keeps calling the default ones instead. And if the default ones are deleted to force the use of the assigned ones my App freezes.

Could you give me a hand with this?