You should post your blueprint setup to https://blueprintue.com so people can actually scroll around and look at things appropriately instead of through a video with you pointing out the nodes step by step. Hard to get a full understanding of the nodes and how they relate. As for the actual issue, pretty sure it is because you attach the grenade to a socket, then animate that socket and you mess up your rotations because the animation does not follow the nice and clean “predicted path”. If you will notice from the attached pics the prediction start location of the socket and the actual release point are very far apart. How can you expect it to make an accurate prediction from those values? Probably going to take some tinkering but I would try and pin down the exact transform of the throw at the point of release relative to the idle position. You will either need to trace from the animation release point for an accurate “arc” and fake the visual to display from the idle position to the target end location or do a bunch of math and calculate the velocity and rotation necessary to reach the end point determined from the idle pose when starting from the rotation and location of the release point.