I'm not sure I understand what you mean by 'not syncing "unnamed."' What are you "syncing" with and by what process?
If the face has "unnamed," then it means that Photos has recognized it as a face, but there's not enough information to determine its identity separate from that of others. If you type in the name, this gives Photos more information to help identify other faces it recognizes.
You can manually circle and name people that haven't been recognized as faces. That will put those pictures in the person's People album, but this ID is not used to inform future identifications.
Do you have some faces that have been identified incorrectly within Photos? If so, Photos will be using bad information, and it will have a hard time with future IDs. Correcting the wrong ones is important, but sometimes the wrong information is so conflated with the the proper identifications, that you have to start over.