Hi,
Well, it's supposed to be "the customer who paid the highest price this month with confirmed orders".
I went and checked the situation since you reported a discrepancy, and I think I found the problem.
I've added a patch on our end.
You can download the install package of HikaShop on our website and install it on yours to get it and it should hopefully help.
Regarding the total orders value, note that it is the number of confirmed orders in the past 30 days. This number is correct on my end.
Thinking about it, I think it would make more sense to have also the "best" section to get the data from the past 30 days instead of the current month to be coherent.