Sometimes imported events, reminders or to-dos appear duplicated in Structured.
In case this happens, please check if your Structured and iOS or macOS are up to date, as this often causes a lot of trouble. This issue also typically occurs when you use Structured on multiple devices. To avoid this, ensure to enable the Calendars and Reminders import on one of your devices only.
You can check this in your ⚙️ Structured Settings in the Integrations section. To disable the integration of your Calendars and Reminders, just deselect them.
With activated iCloud Sync, imported events, reminders and to-dos from one device are still displayed on all devices.