Скрабер ведет себя ненормально

Вот код скрабера

enableDragThumb(): Observable<any> {
    let parentWidth;
    let thumbBarClientWidth;
    const mouseUp = Observable.fromEvent(document, 'mouseup')
        .merge(Observable.fromEvent(document, 'touchend'));
    const mouseMove = Observable.fromEvent(document, 'mousemove')
        .merge(Observable.fromEvent(document, 'touchmove'));
    const thumbBarDown = Observable.fromEvent(this.thumbBar, 'mousedown')
        .merge(Observable.fromEvent(this.thumbBar, 'touchstart'))
        .map((evt: any) => {
            evt = evt.changedTouches ? evt.changedTouches[0] : evt;
            thumbBarClientWidth = this.thumbBar.clientWidth;
            parentWidth = this.thumbBar.getBoundingClientRect().width - 10;
            const left = ((evt.clientX - this.thumbBar.getBoundingClientRect().left) / parentWidth) * thumbBarClientWidth;
            this.thumb.style.left = left - 10 + 'px';
            return evt;
        });
    const mouseDown = Observable.fromEvent(this.thumb, 'mousedown')
        .merge(Observable.fromEvent(this.thumb, 'touchstart'))
        .merge(thumbBarDown)
        .map((ev: any) => {
            ev = ev.changedTouches ? ev.changedTouches[0] : ev;
            parentWidth = this.thumbBar.getBoundingClientRect().width - 10;
            return ev;
        });
    return mouseDown.mergeMap((md: MouseEvent) => {
        this.isDragging = true;
        const startX = md.clientX;
        this.startLeft = (this.thumb.offsetLeft / thumbBarClientWidth) * parentWidth;
        this.progress = (this.startLeft / parentWidth) * 100;
        const result = mouseMove
            .map((mm: any) => {
                if (mm.preventDefault) {
                    mm.preventDefault();
                }
                mm = mm.changedTouches ? mm.changedTouches[0] : mm;
                const left = this.startLeft + mm.clientX - startX;
                if (left < 0) {
                    this.progress = 0;
                    this.thumb.style.left = 0;
                } else if (left > parentWidth - 20) {
                    const percent = ((parentWidth - 20) / parentWidth) * 100;
                    this.progress = percent;
                    this.thumb.style.left = percent + '%';
                } else {
                    const percent = (left / parentWidth) * 100;
                    this.progress = percent;
                    this.thumb.style.left = percent + '%';
                }
            })
            .takeUntil(mouseUp);
        result.subscribe(null, null, () => {
            this.isDragging = false;
            this.updateProgress();
        });
        return result;
    });
}

Когда direction ltr скрабер работает нормально при изменении дирекшна на rtl скрабер ведет себя не нормально Проект на ангуляре, как исправить?