title_body: Kindle highlights not syncing between devices
upvoted_answer: I was able to fix this by removing the book from my iPhone and redownloading it.
  
  Now if I want to see highlights sync immediately between the devices I have to go to the Library after adding a highlight and then go to Library on the other device, press sync and go back into the book. Then a few seconds later the highlight appears. 
  Not ideal but it works.