Issue with Angular mat-option tracking and selection

I'm having a problem with my Angular Material dropdown implementation. When I use the tracking feature in my @for loop, the dropdown displays correctly, but selection functionality breaks.

Here's my current code:

@for(item of _optionData; track item){ 
    <mat-option [value]="item.value?.toString()">
        {{item.text}}
    </mat-option> 
}

I have a condition that works when I mention track: trackbiid, but when I select something, it does not work.

How can I fix this issue so that both tracking and selection work properly? Is there something specific about how tracking interacts with the [value] binding that I'm missing?

how to fix the issues