When I first had my phantom, and now that I have a spark.  Normaly when I do a flight and record video the video will of course save on the SD card. the next flight I took the first flight would autosave to my phone, now it does not.
I have tried to download to the phone with the OTG cable and bluetooth, neither are saving.
The only way to get my video from the SparkSD card is to phycily place it inthe computer.  I can not use the DJI Go$ app to edit to view.

Any suggestion to get the Spark to save the videos to the IPhone 7?

thank you

Try turning on video cache in the settings.