Typescript - Method is undefined

Question

I have angular application and calling one of my methods as callback(i do understand it's not the best practice in Angular but this is not a point of this question).

Inside of my class I have something like this:

My code looks like:

protected updateCtapIctapAdjudication(event: {aidx: number, value: boolean, comment: string}): Observable<AdjudicationResponse> {
  console.log(this.doUpdateCtapIctapAdjudication);
  return this.doUpdateCtapIctapAdjudication(event.aidx, event.value, event.comment);
}

protected doUpdateCtapIctapAdjudication(aidx: number, value: boolean, comment: string): Observable<AdjudicationResponse> {
  console.log('TESTING');
  return of();
}

What error I get:

Which seems to be quite simple code. When I run updateCtapIctapAdjudication() I see console.log inside of that method say that doUpdateCtapIctapAdjudication is undefined and line after that throw error that doUpdateCtapIctapAdjudication is not a function.

This is really strange as method is defined one line below in a same class. I was wondering what I am doing wrong.

What I tried:

As we all do when debugging I tried to simplify code as much as possible and run code below in chrome dev tools and things works fine:

class MyClass {
  updateCtapIctapAdjudication(event) {
    console.log(this.doUpdateCtapIctapAdjudication);
    return this.doUpdateCtapIctapAdjudication(event);
  }

  doUpdateCtapIctapAdjudication(x) {
    console.log('TESTING');
  }
}
x = new MyClass();
this.doUpdateCtapIctapAdjudication();

I'm obviously overlooking something but I don't know what, is there something I should focus on to debug this?