This demo uses imperative chart updates. The generated code is a faithful Angular translation: open it in CodeSandbox to run and tweak.

import { Component, AfterViewInit, OnDestroy, ViewChild } from '@angular/core';
import {
  ChartComponent,
  ApexAxisChartSeries,
  ApexNonAxisChartSeries,
  ApexChart,
  ApexXAxis,
  ApexYAxis,
  ApexTitleSubtitle,
  ApexDataLabels,
  ApexStroke,
  ApexFill,
  ApexLegend,
  ApexTooltip,
  ApexMarkers,
  ApexPlotOptions,
  ApexResponsive,
  ApexGrid,
  ApexAnnotations,
  ApexStates,
  ApexTheme,
  NgApexchartsModule,
} from 'ng-apexcharts';

export type ChartOptions = {
  series?: ApexAxisChartSeries | ApexNonAxisChartSeries;
  chart?: ApexChart;
  xaxis?: ApexXAxis;
  yaxis?: ApexYAxis | ApexYAxis[];
  title?: ApexTitleSubtitle;
  subtitle?: ApexTitleSubtitle;
  dataLabels?: ApexDataLabels;
  stroke?: ApexStroke;
  fill?: ApexFill;
  legend?: ApexLegend;
  tooltip?: ApexTooltip;
  markers?: ApexMarkers;
  plotOptions?: ApexPlotOptions;
  responsive?: ApexResponsive[];
  grid?: ApexGrid;
  annotations?: ApexAnnotations;
  states?: ApexStates;
  theme?: ApexTheme;
  colors?: string[];
  labels?: any;
};

@Component({
  selector: 'app-chart',
  standalone: true,
  imports: [NgApexchartsModule],
  templateUrl: './chart.component.html',
})
export class AppChart implements AfterViewInit, OnDestroy {
  @ViewChild('chart') chart!: ChartComponent;
  public chartOptions: Partial<ChartOptions> = {
          series: [
            {
              name: 'us-east-1',
              data: [
                142,
                138,
                155,
                149,
                151,
                144,
                139,
                null,
                null,
                null,
                158,
                162,
                147,
                150,
                141,
                146,
              ],
            },
            {
              name: 'eu-west-1',
              data: [
                210,
                225,
                null,
                218,
                null,
                208,
                215,
                228,
                null,
                null,
                219,
                null,
                224,
                null,
                null,
                null,
              ],
            },
            {
              name: 'ap-south-1',
              data: [
                null,
                null,
                null,
                null,
                296,
                301,
                288,
                295,
                302,
                310,
                318,
                324,
                305,
                null,
                null,
                null,
              ],
            },
          ],
          chart: {
            height: 350,
            type: 'line',
            zoom: {
              enabled: false,
            },
            animations: {
              enabled: false,
            },
          },
          stroke: {
            width: [5, 5, 4],
            curve: 'smooth',
          },
          labels: [
            '2025-06-04T00:00:00',
            '2025-06-04T01:00:00',
            '2025-06-04T02:00:00',
            '2025-06-04T03:00:00',
            '2025-06-04T04:00:00',
            '2025-06-04T05:00:00',
            '2025-06-04T06:00:00',
            '2025-06-04T07:00:00',
            '2025-06-04T08:00:00',
            '2025-06-04T09:00:00',
            '2025-06-04T10:00:00',
            '2025-06-04T11:00:00',
            '2025-06-04T12:00:00',
            '2025-06-04T13:00:00',
            '2025-06-04T14:00:00',
            '2025-06-04T15:00:00',
          ],
          title: {
            text: 'API Response Time by Region',
          },
          subtitle: {
            text: 'Monitoring dropouts (null values) render as gaps',
          },
          xaxis: {
            type: 'datetime',
            labels: {
              format: 'HH:mm',
            },
          },
          yaxis: {
            labels: {
              formatter: (val) => {
                return val + ' ms'
              },
            },
          },
        };
  ngAfterViewInit() {
    (window as any).ApexCharts.setLicense('APEX-eyJpc3N1ZURhdGUiOiIyMDI2LTA0LTE2IiwiZXhwaXJ5RGF0ZSI6IjIwNTItMDQtMTciLCJwbGFuIjoiZW50ZXJwcmlzZSIsImRvbWFpbnMiOlsiYXBleGNoYXJ0cy5jb20iLCIxMjcuMC4wLjEiXX0=');
  }

  ngOnDestroy() {
    // no cleanup needed
  }
}
Missing / Null Values - Angular Line Charts | ApexCharts.js | ApexCharts.js