Firebase incorrect registration token


I’ve been developing a Ionic app a while ago, and I’m using the Firebase plugin from Ionic.

When I open the app, I have in the constructor of my first page :

if ('cordova')) {
            .subscribe((tok) => { 
                this.token = tok; 
                storage.set('token', tok);

I guess it is working fine; plus, when I display

                .then((val) => { this.debug.push("App token (refreshed): "+val) })
                .catch((error) => { this.debug.push("Error while getting app token: "+error) });

I get a token that seems alright (152 in length, seems to be a number that other people have too).
Lastly, when I use the firebase console to send a message to all the devices, my application receives the notification.
However, if I try to send the same notification to my single device by using this token I’m retrieving, I just get an error saying the registration token is incorrect.

Where could this come from ?

Edit: from a FCM page I’ve seen the following statement:

    // If you want to send messages to this application instance or
    // manage this apps subscriptions on the server side, send the
    // Instance ID token to your app server.

I haven’t done anything of this kind with Ionic because I don’t know if there’s such a command. It could explain easily the problem, but then I would need an answer to it because I haven’t seen an equivalent to that command in the plugin page. If it’s just here to suggest us to store the token in a db, then this is not what I’m looking for. My problem is more like the token has been “uploaded to FCM servers”

And that is where exactly? (Link)

It is this one:

As it mentions this is a wrapper for Did you read through the issues there?

Yes, and the closest one I’ve been able to read was this one:

Not sure this si where my problem come from (can’t test now since updates corrupted my cli in some way) but there seem to be a similar stuff regarding the token that is evaluted as incorrect despite the fact it exists.