Notifications not showing on mobile running Q Beta 5 and Beta 6

[connectiblutz]

Built in Android Studio versions 3.3 and 3.6 Canary 5.

Only changes are updating the gradle plugin and build tools versions.

Pixel with Android Q Beta 5 or Android Q Beta 6 shows no notifications for any type.
Galaxy S10 with Pie works for all 4 notification types.

No errors generated in logcat output while running

2019-08-02 09:50:51.331 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onItemSelected(): position: 0 id: 0
2019-08-02 09:50:52.773 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:50:52.774 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateBigTextStyleNotification()
2019-08-02 09:50:53.414 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:50:53.415 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateBigTextStyleNotification()
2019-08-02 09:52:38.858 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:52:38.859 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateBigTextStyleNotification()
2019-08-02 09:52:39.434 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:52:39.435 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateBigTextStyleNotification()
2019-08-02 09:53:53.871 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onItemSelected(): position: 1 id: 1
2019-08-02 09:53:54.585 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:53:54.586 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateBigPictureStyleNotification()
2019-08-02 09:53:56.677 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onItemSelected(): position: 2 id: 2
2019-08-02 09:53:57.265 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:53:57.266 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateInboxStyleNotification()
2019-08-02 09:53:59.213 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onItemSelected(): position: 3 id: 3
2019-08-02 09:53:59.632 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: onClick()
2019-08-02 09:53:59.633 14066-14066/com.example.android.wearable.wear.wearnotifications D/MainActivity: generateMessagingStyleNotification()