Database transactions not being cleared after test

use Tests\DuskTestCase;
use Laravel\Dusk\Browser;
use Illuminate\Foundation\Testing\DatabaseTransactions;
use App\User;
use Illuminate\Support\Facades\DB;

class PlotsTest extends DuskTestCase {

    use DatabaseTransactions;

    public function setUp() {
        Parent::setUp();
        $this->user = User::find(1);
    }

    /**
     * @test
     * @group plots
     */
    public function loginAsRoot() {
        $this->browse(function (Browser $browser) {
            //$this->user = User::find(1);
            $browser->loginAs($this->user)
                    ->visit('/plots')
                    ->assertSee('Deed Plan No');
        });
    }

    /**
     * @test
     * @group plots
     */
    public function addNewPlot() {

        $this->browse(function (Browser $browser) {
            $browser->visit('/plots')
                    ->click('#add-plot')
                    ->select('#plot-type-id', '1')
                    ->type('#grant-number', 123456852)
                    ->type('#deed-plan-no', 74592169)
                    ->type('#area', 2.5)
                    ->select('#area-type-id', '1')
                    ->type('#term', 33)
                    ->type('#term-from', '1991-05-09')
                    ->select('#granted-to', '2')
                    ->select('#rent-type-id', '1')
                    ->click('#save-plot')
                    ->whenAvailable('.swal2-container', function ($modal) {
                        $modal->assertSee('Plot has been successfully created')
                        ->press('OK');
                    });
        });
    }

}