Excel is not updating formulas jewish and chinese intercultural dating
You may have set the cell formatting to “Text” and then typed the formula in it.
When you set the cell formatting to “Text”, Excel treats the formula as text and shows it instead of evaluating it.
If I had used absolute references, the formula would return the same total for each salesperson, but that's not what I did.
It's a great place to start troubleshooting and could easily have been the problem.
Dogknees was the first to mention that the calculation method might be set to Manual - and that is the problem, but as bill.kuunders mentioned, it gets worse.
Note that copying also into D5 gives an error, since the resulting formula refers to a cell outside col_data (A1: A16).
The same result is obtained in matrix_data2_top_left (I1) with has the advantage of requiring only one cell to be used as a base reference (col_data_top), so extending the source data range with further data does not need redefining the source data range in the formula, one has only to copy-paste into an extended target range.