One potential solution to this problem is to check the settings for your contact syncing process. Ensure that you're using a reliable method for syncing contacts between your Windows 10 device and your Apple devices. You may want to review the settings in both your Windows 10 contacts app and your Apple device's settings to verify that the syncing process is configured correctly.
If the issue persists despite checking the syncing settings, you may want to try a manual cleanup of your contacts. Start by identifying the duplicated contacts and then manually delete the duplicates from your contact list. While this may be a time-consuming process, it can help ensure that your contact list is accurate and free of duplicates.
Additionally, you can consider using third-party contact management apps or tools that specialize in cleaning up duplicated contacts. These apps may offer more advanced features and options for identifying and removing duplicates from your contact list more efficiently.
If you're still unable to resolve the issue on your own, it may be worth reaching out to Official Apple Support for further assistance. They can provide personalized support and may be able to offer additional troubleshooting steps or insights specific to your situation.