angular – Auto complete material How to stay mat-options after selecting an option?

I use the complete angular automatic material

After selecting an option in the list, the carpet options are added, I would like them to remain until I click on the entry. Here is the problem:

insert the description of the image here

My html:

{{B2W account}}
{{B2W account}}

My TS:

constructor () {
this.contasFiltradas = this.contasB2WControl.valueChanges.pipe (
startWith (null),
map ((accountName: string | null) => account name? this._filter (account name): this.contasB2W.slice ()));

private _filter (value: string): string[] {
const filterValue = value.toLowerCase ();
return this.contactsB2W.filter (account => account.toLowerCase (). indexOf (filterValue) === 0);

selected (event: MatAutocompleteSelectedEvent, index: number): void {

this.produtosConfirmedAds[index].contactsB2W.push (event.option.viewValue);

this.inputContactB2W.nativeElement.value = & # 39 ;;