For years I have clicked the bottom right corner of a formula cell and
dragged down the cell and it copies fine.

Today I received a spreadsheet from another person and tried to work on it.
I calculated a formula in a cell. Then I dragged it down the spreadsheet.
The result was that all cells down the page had the same answer as the first
cell I had copied. But each cell had the correct formula in it.

The drag changed the formula, which should have changed the result in the
cell, but it kept the same value as the first cell.

Any help ?? Thanks.