Why is the combined values of the Invoice Total column in the Summary of Outward Supplies (GSTR-1) report different from the Sales row in the Profit and Loss report?

The data shown in the Profit and Loss report is not based of the tax association of transactions (whether tax is applied to a transaction or not). Whereas, the data shown in the Summary of Outward Supplies (GSTR-1) report contains tax-related information such as TDS, TCS, etc.

This is why the combined value of the invoice total column in the Summary of Outward Supplied (GSTR-1) report differs from the Sales row in the Profit and Loss report.