Automatic updates of lookup column data between tables

Automatic updates of lookup column data between tables

Hi,
I'm having some trouble with Reports. I have 2 tables, one with seller names and information about each seller ("Seller Table") and a second table that tracks sales ("Sales Table"). The two tables are linked together through a lookup column, with the Sales Table "looking up" the seller's name for each sale from the Seller Table. The problem that I'm running into is that when I update the name of a seller in the Seller Table, that information is not automatically updating in the Sales Table. I have to go to the Sales Table and manually change the sellers name in that table too despite being linked through a lookup column. How do I get data that is linked through a lookup column to automatically update in every table that it's referenced?
Thanks