not receiving firebase notification from console
Make sure token is generated
FirebaseInstanceId.getInstance().getToken();
I solved the same problem.
The problem seems to be the browser compatibility/version. Mozilla Firefox could easily handle this.
Make sure your app is running in the background.
Open the Firebase notification console in the FireFox browser and send notifications.
check your android app configuration in firebase console
use a restful client to make the request, i suggest chrome-extension://aejoelaoggembcahagimdiliamlcdmfm/dhc.html, there you can see the response of the request, if your request are sent sucessfully or if you have error, and the response tells what kind of error you have
check android app , in the method onMessageReceived and print everything to see if you receive information, besides you can print the property "from" who is the id_number of your proyect, and you can see if the messages come from your firebase android app
check firebase documentation. I've implemented everything just with the guides and its working pretty well