I use the Launch Character node and the Z axis is set to 0. Even so, when launching a target, the Velocity of the target’s Z axis will still be negative and not equal to 0. Why?
Gravity, most likely.
Try disabling physics.
I also guessed that it is related to gravity, so I closed both the collision and the Mesh Enable Gravity, but the problem still exists.
If the gravity in the CharacterMovement is set to 0, then the LaunchCharacter will have a Z-axis rate of 0, but if the gravity in the CharacterMovement is set to 0, the character will be abnormal.