Events added manually into Event Calendar App will always update instantly. Absolutely nothing to worry about there.
There's two main reasons that synced events don't always appear instantly:
Sometimes Google/Apple/Etc calendars are slow to update us about the fact that you have added a new event.
We want your Event Calendar to load as quickly as possible. If we constantly checked for new events every time someone accessed your Event Calendar this could make things significantly slower.
Your widget will update at different intervals depending on where you are viewing it.
Viewing the widget in your admin dashboard
When you are in your admin panel, your calendar will update as soon as we know that you have added new events. This completely depends on the provider. For example, Google tells us about new events straight away, whereas Apple takes a few minutes.
You will still need to refresh the Event Calendar to see new events. You can do this by either refreshing the page or clicking Event Sources -> Refresh Events (scroll all the way to the bottom).
Viewing the widget on your website
We use a technique called ‘caching’ to ensure that your calendar loads as quickly as possible on your website. However, this also means that your calendar won’t update with any new events instantaneously.
We automatically check for any new events or any changes to your events every hour.
If you need some new events to load instantly for any reason. Simply log into your ECA dashboard and go to the editor of your Event Calendar. This will cause a refresh.
If your widget is still not updating after a significant about of time, then please contact us and we can investigate the issue further.