If your download manager isn’t showing the notifications, you can try the notification:
- Tap on Settings
- Choose App & notification > See all apps
- Tap on the ellipse tool and choose Show System
- Select Android setup, clear up the cache and toggle back to the main
- Go to the Download manager app and turn off all the settings
- Reboot the system
- Tap on App and Notification
- Open the Google Play Store and clear up the extra space
- Start downloading the app