If a Calendar Event(s)are not displaying on your Google Calendar but they are displaying on the Calendar in the App, check in the Contact name section and ensure there are not any special characters or numbers there. 

The Contact Name field only supports letters and does not support special characters or numbers. So if there is a special character or number you will need to remove this and then re sync to your Google Calendar.

If the Calendar Event(s) are not displaying on the Calendar in the App, but are displaying on your Google Calendar, check the Location field within the Google Calendar.
If the Location field has a 200 character limit, reducing the Location to less than 200 characters and then re syncing the Google Calendar in the app will display the Events in the App Calendar.