How do I disable character movement?

Hi, so what I’m trying to do is when the character starts they are unable to move for a certain period of time and during that time a typing widget will display. However when I try to disable the character movement I get the error “accessed none ‘callfunc_getplayercharacter_returnvalue’”. Is there any way to fix this with the way I’m constructing my blueprints?
Thanks

I tried this and the player is still able to move around when they enter the trigger box.

Try setting the control target to UI only. If that doesn’t work, try setting the Max Walk Speed to 0.

Where do I set this?