apps-script-samples/solutions/automations/vacation-calendar/ throws error on events that are part of an event series

Summary

I use the script provided here (slightly adapted) to import events from one calendar to another. This works mostly perfectly fine, thank you! But in some cases I get the following error message:

Error attempting to import event: GoogleJsonResponseException: API call to calendar.events.import failed with error: Invalid iCalUID value. Skipping.

My guess is that this happens for events that are part of an event series.

Expected Behavior

The events that are part of the events should be imported. Even if the original event is not in the list.

Actual Behavior

The error mentioned above is thrown.

Steps to Reproduce the Problem

1. Setup the project as described here
2. In the personal calender of a group member add an event series containing at least one of the respective keywords
3. Run the skript

Thanks for your help or for fixing the issue!