title: PrimeNg multiselect drop-down all checkbox behave inconsistent
body: <p><strong>Html Code:</strong></p>
  <pre><code>&lt;p-multiSelect [options]=&quot;selectOptions&quot; maxSelectedLabels=&quot;1&quot; defaultLabel=&quot;Select&quot; [(ngModel)]=&quot;selectedOptions&quot; styleClass=&quot;multiselect-mobileregulation-width&quot;&gt;&lt;/p-multiSelect&gt;
  </code></pre>
  <p><strong>Angular component:</strong></p>
  <pre><code>import { Component, OnInit } from '@angular/core';
  
  @Component({
      selector: 'app-component-view',
      templateUrl: './component-view.component.html',
      styleUrls: ['./component-view.component.scss']
  })
  export class ComponentViewComponent implements OnInit {
      selectOptions: SelectItem[];
      selectedOptions: any;
      ngOnInit() {
              this.selectOptions = [{label: 'Chennai', value: 'chennai'},
              {label: 'Mumbai', value: 'mumbai'},
              {label: 'Mumbai Delhi', value: 'mumbai delhi'},
              {label: 'Kolkatta', value: 'kolkatta'}];
      };
  };
  </code></pre>
  <p><a href="https://i.stack.imgur.com/3Igxx.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3Igxx.png" alt="enter image description here" /></a></p>
  <p>Step1. select a item in a drop down</p>
  <p><a href="https://i.stack.imgur.com/GQAuJ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/GQAuJ.png" alt="enter image description here" /></a></p>
  <p>Step2. search another item (chennai) now automatically all check box selected.</p>
  <p><a href="https://i.stack.imgur.com/No382.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/No382.png" alt="enter image description here" /></a></p>
  <p>Step3. Now check the item (chennai) all check box selection removed.</p>
  <p>I don't know why its behave, anyone please give solution to solve this.</p>
  <p>Thanks in advace.</p>