Expense value in dashboard graph does not reflect reality

Expense value in dashboard graph does not reflect reality

It's hard to explain, but no combination of summing values can give the same result showed on the graph dashboard.
I have some expenses, some of them are equipment, some are tax payable,, and other are simply telephone, etc.
Well, I've tried a lot of combination and couldn't end up with the result showed on the dashboard graph.
Is it possible to schedule a meeting to clarify this point?