Push notofocation to all user ERROR

Hello everyone.
I have a problem sendig a push notification to all the user of my app.
I have more or less 800K token registered in my installation table.
The problem is that I sent a push with no filter in order to reach everyone but there are a lot of device that didn’t receive the notificatio.
I checked in firebase I fund only 270K message sent.
I don’t know why.
May be there is a tuning problem for my parse server or there is a limitation in firebase.
Any suggestion?

Have you checked your logs and _PushStatus collection to see if there is any additional information?