Q: Calendar Invites Keep Reappearing on MacOS Sierra

I am on macOS Sierra 10.12. Calendar is version 9.0. I have two Calendar accounts which are both Google (one is Gmail and one is a company Google Apps account). I have an issue where even when I have taken action on an invite, many of them continue to reappear over and over again in the invites area (see pic with the number "29" above). I reopen the invite bar, and option click them again (so you can "Ok All") to dismiss them all, but then if I restart Calendar or wait a couple of hours, they will reappear again. These reappearing invites are from both accounts. I also use the Mail app with both accounts. How can I make these invites go away for good so that the invite bar only shows truly new stuff?