try deleting the system cache
1. uninstall alexa app
2. powering off the device
3. press the VOLUME UP + HOME + POWER buttons all the same time and HOLD THEM DOWN
4. release only the POWER button when the device vibrates
5. release the other buttons when the ANDROID SYSTEM RECOVERY screen appears
6. using the VOLUME DOWN / UP buttons to navigate, select WIPE CACHE PARTITION
7. press the POWER button, which will act the ENTER key on your keyboard
8. you will likely see some progress notes (at the bottom of the screen in small print) and after about 20 seconds it will likely show DONE.
9. restart the phone
10. reinstall the app.