What you need to know
- Users are seeing sporadic issues syncing Google Calendar services.
- Unclear if issue is specific to third-party clients or also Google's own apps.
- Google's app status dashboard for G Suite customers has not yet been updated.
Google Calendar users are reporting issues syncing their Calendar accounts with third-party calendar apps and services. The gist of the issue is the calendar apps are unable to reach Google Calendar, so they're simply returning a "403" error saying they aren't getting anything back on their API request, or they're failing to sync without notice.
Popular outage reporting site Downdetector is showing a small bump in people reporting issues with Google Calendar, but it doesn't look too widespread at the moment. And considering this (so far) seems like it's specifically an issue with third-party calendar apps, it may not reach a point of being noticed by a large number of people by the time it's fixed.
So for the moment, thankfully if your third-party app isn't syncing with Google Calendar, you can use Google's native Calendar services to get your scheduling done. It doesn't seem as though removing and re-adding, or re-authenticating, a third-party app will do anything to fix the issue. You just have to wait it out.