FCM Notification not coming on ONE PLUS devices if the APP is CLOSED

We are developing an APP where we are using FCM notification.
When the APP is in forground Notification is coming in ONE PLUS device
but not in background or the APP is closed

But the same code is working on SAMSUNG, SONY, MOTO etc..

But when i go to the device battery setting on enable the app for Battery optimization then notification start coming in background also and even the app is closed

Can any one help us out to resolve this issue