I'm getting this error in terminal, in the process of compilation in a angular8 environment.
On the localhost I navigate the page without any problems and without any errors in console.
I made a console.log of the variable that has assigned that dataset property, and it is read correctly.
Below there's the interested code part:

      let timelineEls = document.querySelectorAll('[data-scroll-timeline]');

  scroll.on(scroll, () => {

    for ( let i = 0; i < timelineEls.length; i++ ) {

      let progress = self.getProgress(timelineEls[i]);

      let timelineKey = timelineEls[i].dataset.scrollTimeline;



      console.log(timelineEls[i].dataset);



      let timeline = timelines[timelineKey]._recent;

      let timeline = timelines[timelineKey];

      let duration = timeline.duration();

      if ( progress > 0 && progress <= 1 ) {

        timeline.seek(progress * duration);

      } else {

        if ( progress <= 0 ) {

          timelines[timelineKey].seek(0);

        } else {

          timelines[timelineKey].seek(duration);

        }

      }

    }

  })

console.log stamps correctly this: DOMStringMap {scroll: , scrollTimeline: albed-anim}

Do you have any idea of how to get rid of this error? I guess it's a typescript error but i couldn't find any reasons while it shows and how to avoid it.

Thank you in advance.