you have to use
web.ensureUser(fieldValue.get_lookupValue()) to retrieve user email,user id, and other properties.
Based on your description, I understand that project portfolio list is in the hub site, project status list is in the team site associated with sub site.
If it's like the above, lookup column is not available in this situation.
This is a default behavior in SharePoint.
There is no way to change this behavior using SharePoint out of the box capabilities.
However, you may try customizing the list form using Power Apps which gives you more control over form customizations.