Net present value discounts each cash flow to today and subtracts the initial investment. Comparing only the sum of receipts with the outlay can hide a return that falls short of your target.
An example with numbers
You invest $1,000 and receive $550 at the end of each of the next two years. Discounting at 10%, the NPV is 550/1.10 + 550/1.10² − 1,000, about −$45.45, even though you receive $1,100 in total.
Try it with your numbers
Repeat the calculation at 5%. Notice that changing the required rate changes the valuation even though the expected receipts are the same.
Example figures for learning purposes. They are not a recommendation and do not replace professional advice.