@JS Wolf I'm sorry, I'm not sure what you mean by "validate the code".
I was using Kindle unpack to convert amazon files to epub but my reader didn't like it much (although I have a new one now so maybe that's changed). Even though I could see the epub was fine in Calibre it wouldn't open on my reader. I found that if I convered .azw3 to mobi and then converted to epub from the mobi file just using the standard convert button in Calibre it worked fine. Perhaps a little more unwieldy but I was happy enough and I never had trouble getting books on my reader. But suddenly there are a subset of the .azw3 files which are converting to epub strangely.
@PDurrant
I don't know much about html code or anything like that so I'm hoping the solution will be really simple. Many of the suggestions so far have gone over my head I'm afraid. You are probably right about some paragraph attribute but I don't have the first clue what I'm looking for here or how to fix it. Hence I came to the experts!
