Thank you for providing this. Actually, a bug was observed, occurring in the behavior of the sample app, stating a device is registered whilst it is not. Thus, the option to register the device in Everlive is not presented to the user. This was fixed with manually enabling the PushPlugin from the App's Properties.
Here is a working project that was tested to register a device in the backend project. You have to enter the API key and Google Project number manually.
Could you please test it and get back to us?
P.S. The settings for your project were removed from the previous post, as they are not longer needed.