Standard interface start signal

Hi,

I am trying to run a simple component with standard interfaces but whatever I set the start signal to, the component will automatically run. Does it have to do with the amount/kind of logic in the component?

component unsigned char counter(unsigned char a){
return a;
}

I want to connect the start signal from the CALL conduit to a switch to activate the component but it always runs automatically whatever the control signals are set to.

HLS version: 18.1

Quartus version: 18.1