What we observed was that in cases of devices like xiaomi and oneplus, the app goes into a state of being force killed. So even if the notification sent is one

What we observed was that in cases of devices like xiaomi and oneplus, the app goes into a state of being force killed. So even if the notification sent is one without a data payload ( in which case the app is not woken up ) , the notification will not be displayed to the user. To get around this issue we sent all messages with a data payload to ensure that the app is woken up(or atleast the system tries to wake it up).