Cell linking to and from Primary Columns

Hi all,

I am currently taking my first steps with Cell Linking between sheets.

I have a sheet that contains all of my projects information (54 rows) but the number of columns is getting unwieldy. I decided I needed to separate out some of the information into a separate sheet. I am now creating a Budget Tracking Sheet while keeping the primary sheet as other project information.

I have managed to link cells from the main sheet into the budget sheet with things like Project Name and Location but when I try to link the Primary Column, which has a unique project identifier, I get the following error...

Can you please confirm if Cell Linking is possible either from or to Primary Columns or is this restricted due to the nature of these Primary Columns?