Back button doesn't work

Hello, my back button suddenly stopped working any idea why ?

Is it visible? Are you trying in browser or in mobile/emulator?

Please be clear with the question

it is visible. and it’s on my pc still

Can anyone help please?

You can add back button manually.

<button ion-button (click)="backpage()"></button>
backpage(){
this.navCtrl.push(pagename);
}

but isn’t it supposed to do it on it’s own ???