Sometimes I will stop moving forward, land on one block and still take fall damage equal to the amount I would take if I landed on the next block. Like for instance if I'm traveling towards positive X, I stop on coordinate 7, I will take damage as if I had stopped on coordinate 8. I don't even have to be necessarily moving forward as this happened to me while towering up in the nether and I took like 30 blocks worth of fall damage and died for no reason. I know it was fall damage because the death message was "(my username) fell from a high place"