I use Android so this applies to that version of the Goapp.
I have checked, in the app, the auto clear of Video Cache is enabled, and yet the system tells me that there is no room in the video cache. I guess that is why the videos did not transfer to the app from the quad in my last flight. Pictures did curiously. The flight log did also transfer to the GOapp thankfully.
6300 feet on a 80% battery. It was close to empty when I landed. Good job Quad.
So today using the app I have cleared my SD card of all videos, and will await tomorrow's flight to see what happens. SD card is a 64 GB one.
Is there an explanation as to what the video cache is?
Nothing in the DJI book, and no result here on a search of Video Cache.
Thanks in advance for any advise given.

I've actually noticed this issue in the previous Pilot apps too sometimes.....not sure what causes it.  But if I clear the cache manually and 'start over' it seems to work for awhile....but again, the auto cache clearing feature doesn't appear to work exactly as you would think.

I agree we need more documentation on this feature and others in the DJI Go app.