SAMD21 Pro RF CHG flickering

I’m using a first revision SAMD21 Pro RF. When I plug the board to my computer by USB, the CHG LED turns on with a very fast flicker which slowly turns of the LED. There is no LiPo battery connected and all the headers pads were cleaned to make sure there wasn’t a short there. Is this normal behavior? If not, how may I start debugging the hardware to check for the source of the error?

The LED isn’t staying on after the flicker correct? Does the LED function as expected when a battery is connected?