Content Won't Sync on Your Kindle E-Reader
If your notes, highlights, furthest page read, and collections aren't syncing across your devices or Kindle reading apps, you may have synchronization turned off on your Kindle or Amazon account, or you may not be connected to a wireless network. Help for any Kindle e-reader model (6th Generation and newer).
To sync your Kindle content:
Make sure that Whispersync for Books is enabled on your Kindle. From the Home screen, tap the Menu
icon > Settings > Device Options > Advanced Options. If Whispersync for Books is Not Enabled, tap this option and select Enable.
Make sure that Whispersync Device Synchronization is enabled on your Amazon account. From your computer, go to Manage Your Content and Devices and select Settings. Under Device Synchronization (Whispersync Settings), verify that Whispersync Device Synchronization is turned ON.
Check the status of your wireless connection. You can view the wireless indicators from Home or any Settings screen. If you're reading, tap the top of the screen to view the indicators. To learn more, go to Check the Status of Your Wireless Connection.
Check your software version. If your Kindle is not on the latest software version, you will need to update your device to the latest available version. To learn more, go to Fire & Kindle Software Updates.
Manually sync your device. While reading, tap the top of the screen to view the reading toolbar, tap the Quick Actions icon (cog), and then tap Sync My Kindle.