Motion blur rendering problem

I'm having an issue with an old project I recently re-opened. I scaled the comp from 405 to 1080. Everything was vector so it scaled beautifully, BUT when I go to render, the motion blur is "sticking" on some words. In the screenshot above, see the "but did" before "he go"? The words flew on from off the screen and have stopped. They should no longer have any motion blur, but it's stuck there. When I purge the memory and cache, it updates and disappears, but as soon as I try to render again, it sticks again.

Any suggestions to force the motion blur to disappear as normal when the word stops moving? The rest of the words (in this sentence) are fine. This happens multiple times throughout the composition, so it's not just this one layer.