[exaltedwombat]

A client just forwarded this to me. Haven't seen anything like this before. Book was made in Sigil, converted to mobi in Kindle Previewer 3.

I suspect it was because I'd used some section headings with a distinctive css style but not tagged them as a header style.

Alright, so I won't do that in future. But this book had been in the Kindle store for a year. Are Amazon tightening up their standards retrospectively?