title_body: Why/Where is calibre writing author/title in metadata when saving to device?
upvoted_answer: I had trouble with metadata from Calibre until I realised that I had to either reconvert or polish the ebook after making any changes to the title, author, description etc. 
  
  For the metadata to "stick" you have to polish (in the case of an epub) or convert (in the case of a new book in other than epub format).
  
  Although the metadata will look fine in Calibre, if you've made changes you need to polish or convert for the changes to be applied to the ebook.
  
  Hope this helps you.