I was about to buy a kinddle just for my PM books when I realized this issue.
I couldnt fix the issue to go into kinddle without paying, but I think I find a better alternative.
PDF files nowadays have the voice reader option with works much better for me than kinddle, I can still use my PC or phone but now I can study on the car.
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®