[Solved]-Highcharts inactive state must be applied to all items except for hovered item-Highcharts

You can loop through points from the active series and set their state to inactive:

    plotOptions: {
        series: {
            point: {
                events: {
                    mouseOver: function() {
                        const point = this;

                        point.series.points.forEach(p => {
                            if (p !== point) {
                                p.setState('inactive');
                            }
                        });
                    },
                    mouseOut: function() {
                        const point = this;

                        point.series.points.forEach(p => {
                            if (p !== point) {
                                p.setState('normal');
                            }
                        });
                    }
                }
            },
            ...
        }
    }

Live demo: https://jsfiddle.net/BlackLabel/fsdw21em/

API Reference: https://api.highcharts.com/class-reference/Highcharts.Point#setState