From the video it is hard to tell. There is no blueprint visible.
But i think it has something to do with your characters animation blueprint.
As soon as you character reaches the corner of the platform it blends the move forward animation out into the “falling animation” and only starts falling after the falling animation. This is just a visual perception. While this blend happens, the character seems to be stuck.
Anyway - the movement is unnatural. I would expect to see a parabolic flight path of your character dropping of the edge. But it goes full stop and then straight down.
Ho do you handle “falling down”? Something is odd here.