indeterminate checklbox

[vytautas-pranskunas-]

Hi,
i am trying to do indeterminate checkbox and it looks easy. I narrowed it to a minumum: https://stackblitz.com/edit/angular-cd7dtf1t?file=src%2Fapp%2Fapp.template.html,src%2Fapp%2Fapp.component.ts,src%2Fmain.ts

however in my code it indeterminate state is not shown

<label tuiLabel class="select-all-checkbox-multi-select">
            <input
                tuiCheckbox
                type="checkbox"
                [ngModel]="null"
                [indeterminate]="true"
                (click)="toggleSelectAll($event)"
            />
            Select All
            <!-- {{ 'appeal-edit.contactByEmail' | translate }} -->
        </label>

it does not matter what value i provide to ngModel (i suppose it has to be null anyway in order to see indeterminate state)
Please advice

[vytautas-pranskunas-]

solved that.. it was styling issue

[waterplea]

Checkbox is showing indeterminate status when control value/ngModel is null