If your USB port cannot supply 500mA, then you might experience this. Not knowing what you have connected to the board, things in the USB port for example, you can easily go over the USB current. As indicated in the SRM, it is close to the 500mA limit. Very close. There is a limit to what you can do using USB power. When powering over USB or DC, there is only one component, the PMIC, that switches either USB or DC to power the board. It is a FET switch. The only defect I can think of would be that the USB would not power it at all due to a damaged FET. That does not appear to be the case. If it runs fine on the DC jack, giving plenty of current, it is not likely the board is defective. Otherwise, it would not work on DC either.
My suggestion is to use a current meter while running via the DC jack, and see how much current it is consuming in your use case. A peak hold setting would be ideal to see what the peak current is.
Gerald