Can't stop the Update Links? startup prompt

I have an Excel workbook that resides on a network drive for many users to
access with links to another workbook. I wanted to turn off the "Update
Links?" dialog box which pops up on opening so I went to Edit> Links> Startup
Prompt and disabled it. Except it didn't. Unless the linked sheet is already
open I am still prompted to update the links. Did I miss something?

The alternative of going to Tools>Options>Edit> Ask to Update links is not
an option due to the # of users.

Thanks for your help