Walk speed doesn't change after changing MaxWalkSpeed

Development Programming & Scripting
1

I have a custom character class inheriting from ACharacter.
When i use “AddMovementInput(DirectionVector, SpeedValue)” the character moves forward. But by changing the SpeedValue, or by setting

GetCharacterMovement()->MaxWalkSpeed = 1000.0f;
or
GetCharacterMovement()->MaxCustomMovementSpeed = 1000.0f;

the walk speed still remains as before.
I also made sure that the maxwalkspeed acually changed by printing its value after setting it.
Am i missing something with e.g. any neccessary setup for the charactermovementcomponent or why does the walking speed not change?