M300 Flight Not Uploading

Hello, I am trying to upload a flight from the DJI Smart Controller, with the latest Pix4Dscan app installed, to a DJI M300. I have uninstalled and reinstalled Pix4Dscan multiple times with no success. It gets to the “uploading mission” pop-up and just sits there. Any ideas what the problem might be? Drone and controller firmware is up to date as well.