The image geolocation the image EXIF is not accurate because DJI truncates some decimals when writing the coordinates. GPS milliseconds are not taken into account so several images end up with similar coordinates. Also note that these drones do not measure altitude so the elevation of the model cannot be fixed.
This is why it is recommended to process the images from the project file (.p4d) that is generated by Pix4Dcapture. Both planar and vertical accurate coordinates are written in the .p4d file.
Besides transferring the images, it is needed to transfer the .p4d file from the device to the computer. For more information: (Android, iOS) How to transfer and process images after the mission. With the iOS app, it is also possible to send the .p4d file by email. For more information: (iOS) How to transfer the mission .p4d file directly from the Pix4Dcapture.