Android devices do NOT receive push notification from Airship dashboard

Follow

When sending a push notification from UrbanAirShip to all devices, android devices do not receive thus notifications,

Details:

Android build uses AirShip version 14.5.1

google-services.json properties all are the same, nothing different

The android app uses firebase services:

• firebase-crashlytics:17.3.0'
• firebase-analytics:19.0.0'
• firebase-messaging:22.0.0'
• firebase-core:19.0.0'

Android build details:

• minSdkVersion = 21
• targetSdkVersion = 29
• builToolsVersion = '28.0.3'

APK details:

• Debug build.

Airshipconfig.properties details

• fcmSenderId & gcmSenderId are the same as the firebase project for this app and in airship setting page.
• Server Key in firebase cloud messaging is the same as server key in the airship settings page.
• developmentAppKey & developmentAppSecret are the same in airshipconfig.properties and airship settings page.
• inProduction flag is false to use development app key and secret as configured.

Device details:

• Samsung S8, Samsung s7
• realme pro 2   Android 10.
• emulator, pixcel 2 Android 10
• All devices are connected to the internet with high bandwidth. (tested by speed test website).