Hi Bryan,
Thank you for your feedback. Please note that the Phantom 4 Pro + is not officially supported by Pix4Dcapture. Users have been able to make it work quite nicely though using our application.
I would suggest you to have a look at this thread on our community and especially at this comment where a user is explaining how he made it work.
You can get more information on how to prepare a free flight mission here.
Also, I would suggest you the followings:
- Restart the mission from scratch. To do so, close and force quit the app, disconnect the mobile device, turn off the remote controller and the drone. Then respectively switch on the drone, then the remote controller and finally Ctrl+DJI and Pix4Dcapture.
- Make sure that the drone app is not running in the background. You can follow-up this procedure.
- Go through the basic checks and troubleshooting.
Best,