Earlier quoted context omitted.
> When it started deleting books i had side-loaded via calibre Could you expand on that? I load all my books via calibre but I also have the kindle set to aeroplane mode at all times. Does this happen when syncing?
It deletes all side-loaded books when you connect it to the internet, happened to me as well.
Fortunately, getting two units in a row with jarring pink blotches was enough of a non-starter to suggest that she just revert to a V4 without my having to explain the confusing behavior.