That's the thing, the player wasn't moving intentionally, the knockback from being suffocated automatically pushes the player out.
This problem doesn't seem to exist in the non-beta version.
Is it configurable? What is it called in the config if so?
Suffocate:
Enabled: true
Description: This ability is one of the most dangerous abilities an Airbender possesses. To use, simply look at an entity and hold shift. The entity will begin taking damage as you extract the air from their lungs. Any bender caught in this sphere will only be able to use basic moves, such as AirSwipe, WaterManipulation, FireBlast, or EarthBlast. An entity can be knocked out of the sphere by certain bending arts, and your attention will be disrupted if you are hit by bending.
Range: 15
Damage: 7
ChargeTime: 0
Cooldown: 0
DamageInitialDelay: 2
DamageInterval: 1
SlowPotency: 1
SlowDelay: 0.5
SlowInterval: 1.25
BlindPotentcy: 30
BlindDelay: 2
BlindInterval: 1.5
CanBeUsedOnUndeadMobs: true
RequireConstantAim: true
RequireConstantAimRadius: 5
AnimationRadius: 2.0
AnimationParticleAmount: 2
AnimationSpeed: 1.0
This is the piece of the config file that allows you to edit the "hold range" of suffocate. It is beneath the description. All of the other elements here are configurable.