If you are using the character movement component, simply increase ‘Braking Deceleration/Falling’ under CharacterMovementComponent/CharacterMovement: Jumping/Falling. Would be great to hear if that’s what you want 
Is There a Way to Apply "Stop Movement Immediately" When There Is No Player Input For Specific Keys?
I’m making a platformer and I basically want to replicate this type of movement, in which velocity is cancelled when the player is no longer influencing the player character, but only when moving left and right. Left and Right arrow keys. I want to stop all movement immediately, but only when those two keys aren’t being pressed
Yes, that was actually what I was looking to achieve, thank you so much!