Movie render queue MotionVectors pass doesn't work.

I trying to use the MotionVectors pass as it’s describe here Movie Render Queue Enhancements in 4.26 | Inside Unreal - YouTube
But when i render my sequence, the motionvectors pass is all yellow/greeny. It’s like there is no motion at all.

When i’m in real time, i display the motionVectors pass as a post process material in my postprocessvolume, it works while i play it, but when i hit pause, it’s again, all yellow/green because there is no motion anymore.

I don’t understand why i can’t render it.