I can't see where n+1 problem occurs

Error :

My method :

    public static function employee_of_the_month($minus = 0)
    {
        $employee = EmployeeMonthlySales::query()
            ->where('month', month_substract($minus))
            ->where('year', get_year_by_sub_month($minus))
            ->orderBy('total', 'desc')
            ->first();
        return collect([
                'name' => $employee->employee->name,
                'total' => $employee->total
        ]);
    }

I'm calling this method 2 times from my controller, one for employee of the month for current month, and one for previous month. I'm getting a n+1 alert from a package I installed, it goes away when I remove the $employee variable and return the collection as string.

Ps : I obviously tried adding ->with('employee') and ->with('employee:id,name'), still shows n+1