Work down this list. Nearly every surprising profit figure is one of these six, and the first two account for most of them.
1. Orders without a buying price
An order with no cost entered is excluded from profit entirely — it is not counted at zero cost. So your profit figure covers fewer orders than your revenue figure does.
Check the amber strip on the dashboard panel: "N orders awaiting buying price · £X of sales not in this profit yet". That is the gap, stated. Price them and the figure moves.
2. Fees that have not arrived yet
eBay publishes fees after the order. A sale from the last hour can show its sale price with no fees against it. Baiord pulls finances every 15 minutes, so wait a little and look again.
If the Fees column says unavailable, that is different and permanent — see the 90-day limit.
3. Expenses are prorated through the month
Partway through a month, only the days so far are deducted. The Expenses page spells out the daily figure and where you are. This is the usual reason net profit looks "too good" mid-month.
4. A refund landed in a different month than you expected
A July sale refunded in August reduces whichever month your refund attribution setting says. The dashboard breakdown prints which basis it is using at the bottom.
5. A prior-period fee adjustment
eBay settles Promoted Listings weeks later and hands fees back on refunds, so fees booked this month can belong to last month's orders. Those appear on their own row — Prior-period fee adjustments — rather than being folded in. Open See breakdown and look for it.
6. A supplier refund recorded twice
If you recorded a supplier refund as received and cleared the order's buying price, the same money is counted twice. The cost history panel on that order warns you when it sees this.
Still wrong?
Open See breakdown on the dashboard panel. Every row is clickable and shows the individual orders and transactions behind it. The row where the number stops matching your expectation is the row to look at — and then tell us the order number.