StatisticController.php

<?php
namespace App\Http\Controllers;

use App\Statistic;

class StatisticController extends Controller
{
    public function stats() {
        $period = request('period');

        $statistics = Statistic::select('columns')
            ->where('Period', $period)
            ->orderBy('PeriodDate');

        $statisticsCurrentYear = clone $statistics; // falla el resultado final
        $statisticsPreviousYear = clone $statistics; // falla el resultado final   
      
        // más código aquí
    }
}