In Zoho CRM, I went to settings, marketplace, then Google. I configured it to sync both ways with a new google calendar. It accepted the setup and synchronized but only some activities actually synchronized. 

From the attached image you can see it's missing 2 items on Friday the 18th. It's also missing items from other day as well. I've refreshed the page and checked the configuration again. I don't understand what's wrong. 

Any assistance would be great. Thanks.