I have a spreadsheet with about 20 columns and 8,000 rows. I have numerical
data in most of the columns corresponding to people. Like this:

John 9 6
Debbie 9 5
James 8 5

Total 26 16

If I highlight all columns and do a sort by the person's name, the total
number at the bottom changes even if the data has not changed. Do you know
why this is happening?

Thanks in advance for any help!