Hello, I'm Greg, here to help you with this.
It could be a bug. Are the duplicates in Windows 11, Android or both? Since it syncs the data between them, it should be in both. So you can merge duplicates in Android and see if it sync's to PC:
https://support.google.com/contacts/answer/7078...
Let me know what happens. If you want to report this as a bug to Microsoft use the Feedback Hub app in Start Menu where developers are tasked to process consumer feedback. They will not even see it here. Microsoft developers DO read feedback from customers that comes in via the Feedback Hub, so that is a great way to share your thoughts on how to better serve you as a customer.
Feel free to ask back any questions. Based on the results you post back, I will have other suggestions if necessary.
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