Android alarm not working until I activate my screen by pressing the lock button

Configuration
,
1

Hi,

I have a HA setup with Raspberry Pi 4 and a Z-Wave usb stick.
I have an automation where I want an alarm to go off on my android phone when one of my smoke detectors detect smoke.

I have the following entry in my automations.yaml:

- id: 'XXX'
  alias: Send notification to phone in case of smoke alarm
  description: ''
  trigger:
  - platform: state
    entity_id: sensor.rooksensor01_smoke
    to: '2'
  - platform: state
    entity_id: sensor.rooksensor02_smoke
    to: '2'
  - platform: state
    entity_id: sensor.rooksensor03_smoke
    to: '2'
  action:
    service: notify.ALL_MOBILE_DEVICES
    data:
      title: 'Warning'
      message: 'A smoke detector was triggered!'
      data:
        color: 'red'
        ttl: 0
        priority: high
        channel: alarm_stream

This automation works pretty well and an audible alarm sound + notification appears on my phone, BUT when my phone is locked/standby, the notification/alarm sound only appears when pressing the lock button on my phone which turns on the screen. Then the alarm/notification appears immediately.

Obviously I want to hear the alarm on my phone at any time, even when the phone is in standby mode.

I thought this would have something to do with the app suspending in the background, but I have disabled all power saving options for the HA app.

Anyone with similiar experiences?

My phone is a OnePlus Nord AC2003.

Thanks!