Even though set up as per the DJI GO 4 Manual my P4PV2.0 does not record very loud Steam Locomotives whistles. Is it really a feature that works?

If you have it enabled on your device then you can use cached video in post edit, the actually sound is not reorded on the SD card but on the cached file only

Hi. Thank you for reaching DJI Forum. I agree with the #2 post. You can only hear the sound in the cached files.

Even though I started out with a P3P over 2 years ago followed up with a P4 and now my new P4PV2.0, I also have a I1V2 and a MP but I've never worked with Cached Files. Where do I start?