Nunit: TestCaseSource is not waiting generate all test cases?

Hi everyone I have a problem with generate test cases for TestCaseSource. I wrote this code for tests:

using System;
using System.Collections.Generic;
using System.Linq;

using NUnit.Framework;

namespace HeapSort.Tests
{
    [TestFixture]
    public class Tests
    {
        [Test, TestCaseSource(typeof(TestsGenerator),"TestCases")]
        public void IsEqualCollections(int[] received, int[] expected)
        {
            CollectionAssert.AreEqual(received, expected);
        }
    }

    public class TestsGenerator
    {
        public static IEnumerable<TestCaseData> TestCases
        {
            get
            {
                for (var i = 0; i < 25; i++)
                {
                    int[] t1 = GenerateCollection(i), t2 = t1.ToArray();
                    HeapSort.Sort(t1);
                    Array.Sort(t2);

                    yield return new TestCaseData(t1, t2);
                }
            }
        }

        private static int[] GenerateCollection(int seed)
        {
            var rnd = new Random(seed+DateTime.Now.Millisecond);
            int size = rnd.Next(100, 10000); 
            int[] array = new int[size];
                for (var i = 0; i < size; i++)
                    array[i] = rnd.Next(-100, 100);
            return array;

//            return Enumerable
//                .Repeat(100, rnd.Next(100, 10000))
//                .Select(i => rnd.Next(-100, 100))
//                .ToArray();
        }
    }
}

Is there a problem? Instead of getting 25 tests I get from 1 to 8, and often at the initial point of testing it shows that the tests are 7/8, and at the end there is only one test case.

How i can solver it?

P.S. Sorry for my bad English.

Perhaps it is worth mentioning that I work on Ubuntu in Rider