You are not receiving notifications about documents being shared with you. Other colleagues are receiving email notifications when the same files were shared with them.

Google Drive (Web)

Use Google's Get Google Drive notifications article to change the notifications settings. https://support.google.com/drive/answer/6318501?hl=en

1. Go to drive.google.com.
2. In the top right, click Settings > Settings.
3. In the left panel, click Notifications.
4. Check the box to enable email notifications. 

Google Drive setting prevented email notifications from sending.