Hello and welcome to the QuickBooks Community, LC1167
Widgets are designed to offer a snapshot figure and can include different data and date rages in comparison to reports such as the P&L. When you click onto the widget, the full report that the figure(s) relate to will load.
The sales widgets won't include any transaction that doesn't have a sale/expensive VAT code assigned (e.g. NO VAT) and is based on the accrual method, meaning all paid or unpaid invoices, sales receipts, and deposits using a sales vat code will be accounted for on this widget.
We hope this offers some guidance on the reasons for the discrepancies, however, if you need any further assistance, please don't hesitate to get back in touch. Thanks again for contacting Intuit QuickBooks Community.