My update function in my controller is not run at all

I created my model with this command php artisan make:model BuildingOnRent -mcr which created the controller and the resources.

In my web.php, I passed the resource route like this

My web.php

Route::resource('br', BuildingOnRentController::class);

In the controller scaffolded by Laravel herself, I added the code under the update function like this.

My controller

public function update(Request $request, BuildingOnRent $br)
    {
        echo $br;
        $request->validate([
            'purpose'=>'required',
            'rooms'=>'required',
            'bathrooms'=>'required',
            'parlour'=>'required',
            'rent_period'=>'required',
            'cost'=>'required',
            'city'=>'required',
            'state'=>'required',
            'locate'=>'required',
        ]);
        dd($br);
        $br->update($request->all());

        return redirect()->route('br.index')->with('success','Property updated successfully');
    }

My edit.blade form action

action="{{ route('br.update',['br'=>$br]) }}"

When I fill and submit the form in the edit.blade, hence triggering the update function in the controller, I am redirected to the route br.index but nothing is updated. In fact, the update code is not even run as I tried to echo $br and dd($br) but nothing was echoed or dumped. I take it that the update code is not run at all.

Why is the update code block not run?

How can I make it to run?

I am using laravel 10. Please help out.