Did you recently purchase it?
Did it work before and now is having issues?
If it had issues right out of the box I would say it is an issue with the Shield image flashed on to the SD card. Making a software assumption as it is hard to diagnose a potential hardware issue from here.
If you have a micro SD adapter around the house, with a little elbow grease you can reflash the card yourself. Instructions are at the bottom of this page. Simple!
I’d reach out to the Reverb seller as well, see how they want to remedy the issue and give them a heads up regarding the QC.
Plenty of people around here that are happy to help. Keep us posted!