The unit of duration in "transition" is second, not millisecond.

Code
Code Overrides
Framer
Updated: 2018-09-01

No wonder why the animation stopped working as soon as a duration is added. It's not broken, just VERY slow.🤦‍

// This animation will last 10 minutes, not 600 milliseconds!
<Frame animate={{ opacity: 0 }} transition={{ duration: 600 }} />