Disabled not working

When using attr.disabled, you have to supply the literal value, or omit the attribute altogether. Bear in mind that the disabled attribute in HTML disables an element that supports the attribute simply by being present.

<input [(ngModel)]="osoba.ime" [attr.disabled]="disabled?'':null" name="ime" type="text" id="ime">

Both of the following in HTML should result in an input being disabled...

<input disabled />
<input disabled="disabled" />

Use this :

 <input
    type="radio"
    id="primaryIPV6"
    value="2"
    [attr.disabled]="flagValue ? '' : null"
    formControlName="p_ip_type"
    (change)="optionalFn()">