It can take up to three days (72 hours) for your cover image to show up on your product detail page. It's normal for the detail page to show up a bit before the cover image does. The cover image in the "Look Inside" sample can take up to a week to update.
https://kdp.amazon.com/help/topic/A2J0TRG6OPX0VM for image info
- 0 Users Found This Useful