Negative Selling Amount

Hello, any idea why do i have a negative number in the selling amount? (-30,000)
Taking into consideration all my sales invoices are correct :

You make it much easier for forum members if you show more information.
I think what you show now is the part of a report.
The amount -30,825.23 contains no quantity numbers and will have been generated by the construction of your report.
So maybe we can serve you better if you show the structure of the report.

How do you think anyone could help when you show a list of figures that could be anything ?

You need to show a lot more info to get any help

Also, state what edition (desktop, server, cloud) and version of Manager you are using

Which report is this