Need to add additional fields for SharePoint lookup field so that use those additonal fields in Linq queries.
Sometimes the result from Linq queries for those additional fields are wrong, just need to remove them and add them again in List Settings.
For Example, In List “Staff” there is a lookup field “Customer” which Looking up information from list “Customers”, and also get additional fields “Address”, “Suburb”, “State” from list “Customers”.
If you get incorrect information when you get Customers.Address or Customers.Suburb using Linq. You will need to go to List Settings in list “Staff”, remove the additional fields, and add them again.