tradThis is the most frequent reason people write to us, and in the great majority of cases both numbers are right: they are not measuring the same thing.
Four causes, in the order we check them.
TIME ZONE. A broker statement is dated in the server's time zone, not yours. A trade closed late in the day can therefore land the day before or the day after depending on who displays it, and a monthly total shifts by an operation or two at the edges. This is the first thing to look at when the gap sits on a boundary day.
FEES AND SWAPS. Depending on the broker, commission and swap arrive on the trade line, on a separate line, or at the end of the day. A gross P&L and a net P&L do not compare, and the gap grows exactly with the number of trades.
PARTIAL POSITIONS. Entering in three steps and exiting in two is five operations at the broker. The journal groups them into one position, because it was one decision. The number of trades therefore differs, without either side being wrong.
THE ACCOUNT. A demo login and a live login look very much alike, and a connection set on the wrong one produces a perfectly coherent history that simply does not match the statement in front of you.
If the gap survives those four checks, write to us: at that point it is a defect on our side, and we want to know. The useful message names the broker, the period, and one specific trade that differs.