droid turbo 2 and Amazon Kindle

[AC Question]

Amazon Kindle app got stuck in landscape mode and won't go back. It's only when reading a book every other screen rotates appropriately, and before some posts about the lock icon in the lower right corner ill go ahead and tell you I've looked for it, and it's either not there or its covered by my pop up back, home, and tabs buttons and i can't see the lock