Angular storybook and rxjs

I have created an Angular project in which I have one or more "smart" components.

These components accept a BehaviorSubject from the parent component (for various reasons) in @Input.

In this way, at the "next" of the BehaviorSubject, the value inside it is processed in various ways by the child component.

All good except that it was decided to use storybooks for the presentation of the components.

This is a problem because the "args", if modified, send in input a new value different from the BehaviorSubject and the component functioning stops.

Is there a way to trigger a .next () to change a specific arg?

The story code below:

const someConfig$ = new BehaviorSubject({someInstructions: 'instructions'});


export const defaultTemplate = template.bind({});
defaultTemplate.args = {
    someConfig: someConfig$
};