.NET 5.0 breaking changes regarding `IEnumerable.OrderBy` behavior on string comparison

I have below code

    public class Model    {        public int Id { get; set; }        public string OrderNumber { get; set; }    }    class Program    {        static void Main(string[] args)        {            var models = new List<Model>            {                new Model {Id = 4, OrderNumber = "BT-3964-1"},                new Model {Id = 2, OrderNumber = "BT3924"},                new Model {Id = 1, OrderNumber = "bt3810v2"},                new Model {Id = 5, OrderNumber = "BILL-TEST100"},                new Model {Id = 3, OrderNumber = "BT-4887-Test3-Create"}            };            var reorderedModels = models.OrderBy(x => x.OrderNumber);            Console.WriteLine("The sorted models are:");            foreach (var model in reorderedModels)            {                Console.WriteLine($"OrderNumber: {model.OrderNumber}, Id: {model.Id}");            }        }    }

In .NET Core 3.1 and 2.1, it gives below output

The sorted models are:OrderNumber: BILL-TEST100, Id: 5OrderNumber: bt3810v2, Id: 1OrderNumber: BT3924, Id: 2OrderNumber: BT-3964-1, Id: 4OrderNumber: BT-4887-Test3-Create, Id: 3

But on .NET 5.0, it gives below output

The sorted models are:OrderNumber: BILL-TEST100, Id: 5OrderNumber: BT-3964-1, Id: 4OrderNumber: BT-4887-Test3-Create, Id: 3OrderNumber: bt3810v2, Id: 1OrderNumber: BT3924, Id: 2

Why the breaking changes?

Additional Note: even using OrderBy(x => x.OrderNumber, StringComparer.InvariantCultureIgnoreCase), this issue still happens