The API for that call says it’s clamped to what’s set in the device. What is your magnitude set to on the device itself?
# Used to increase or decrease a stat for an `agent`.
stat_powerup_device<public> := class<concrete><final>(powerup_device):
# Sets the *Magnitude* for this powerup, clamped to the Min and Max defined in the device.
# Will not apply to any currently applied effects.
# For the Stat Powerup, this is the value of the stat that the powerup will add or remove to a player that picks up the powerup.
SetMagnitude<public>(Magnitude:float):void = external {}
# Returns the current *Magnitude* for the powerup.
# For the Stat Powerup, this is the value of the stat that the powerup will add or remove to a player that picks up the powerup.
GetMagnitude<public>()<transacts>:float = external {}