Arducopter won't recognize GPS with Marvelmind

Hi all!

I am new to the drone space and I am trying to fly autonomously indoors. I purchased the Marvelmind system and currently have one hooked up to the drone as per Marvelmind’s Pixhawk Integration Manual. I have also followed the instructions on the Ardupilot page. I have 3 super-beacons around my space, each around 2 meters up (with height configured properly in the map), and the Marvelmind dashboard accuractely tracks the hedgehog on the drone. However, when I connect through the Mission Planner, the HUD says “GPS: No GPS” and the map does not show the copter anywhere. The firmware is fully updated on all the beacons and the Pixhawk is running 4.2.2. What am I missing?