Excel Creating Unwanted Links in Equations after Save As

The problem I'm facing is made more difficult by the fact that it's not happening to me and I was only made aware of it after the fact.  One of the other people in my office is having an issue where Excel seems to be inserting unwanted links into equations all on its own when this person uses the Save As to save the file to a new name.

To give an example, say the file was originally named "Hello" and it had an equation in a certain cell that read '=B3'.  After a Save As was done to make a new file called "Hello 10-19-18", even though the file is now "Hello 10-19-18", that cell with the equation to grab B3 now says "='[Hello.xlsx]Balance'!$B$3" (referencing the original file name) instead of the original '=B3'.

I've never seen this happen before and it's such a unique circumstance that trying to search for keywords to find answers is turning up way too many completely unrelated results.  While I can't rule out the possibility of human error entirely, I've been told that this same issue has been happening regularly with equations in all the Excel spreadsheets with which she's been working, which seems to indicate it's something systemic. 

Is there possibly a setting in Excel that could explain why a file might continue to reference the old file's cells after you do a Save As to save the file to a new name?  Any thoughts or advice would be greatly appreciated.