Push Notification - unclear receiver
If one has in "user" more than two telefon numbers, than you will get also two options while creating a push message as receiver. If your second telefon number is the mobile, then you will get your push message only if you select the the second option in the list of receivers. Unfortunately both options have the same name of the user in the list.
Idea: in the drop down list of users there should not be only the name but also which telefonnumber is meant. This is valid only for push messages.