My WhatsApp media (photos and videos) gets corrupted when I move and copy them from their default location to the external SD card. The photos and videos behave properly for some time before becoming greyed out and unrecoverable. Moreover, it is very puzzling to me that this does not happen with all of the transferred/copied WhatsApp media. While majority of the files get corrupted and unusable, some of the files are good. I have no idea why this is happening. Could anyone shed more light on this issue? I have a Galaxy Grand Prime +.
EDIT 1:
This answer looked useful but it claims a faulty SD card to be the cause. Moreover, my issues seem to be occurring only with WhatsApp media.
EDIT 2:
I took photos from my camera and put them in my SD card and even those photos got corrupted. So the problem is not confined to WhatsApp.