Notifications not showing on Android 5.1

[realcarlos]

I run the sample code in the folder ,and I could see some buttons ,but when I click the 'Create basic notification' button , it just plays vibrate , I can see nothing displayed.

[mitchhymel]

When you say nothing is displayed, do you mean that you don't see a heads up notification (like this?) or you don't even see the notification go to the status bar (like in this gif)? I haven't tested on Android 5.1 yet but I don't know of any android API changes that would explain the different behavior.