Hello, thank you for reaching out to Microsoft Q&A.
Just to confirm, are you referring to the Outlook app or the Phone Link app when syncing contacts from your iPhone?
After you’ve successfully paired your iPhone with your Windows desktop using the Phone Link app, you’ll need to grant permissions for Phone Link to sync your contacts and display call history on your PC.
If you haven’t granted these permissions, go to Bluetooth settings on your iPhone, select your desktop name, and turn on the toggle for Sync Contacts. Make sure All Contacts is selected. You can also enable Phone Favorites and Phone Recents if you want.
Once this is done refresh the Phone link app and then you can use the dialer search bar in the Phone Link app to search for your contacts, and the results should be displayed.