Custom attribute isnt found during test collection ordering - xunit

Im running E2E tests with some of the logics written using xUnit (.NET 8, c#) and need the tests to run in particular order. Id like to control the order in 2 ways: test case and class - and it needs to be ordered by numbers (int that is). This is the test case attribute: [AttributeUsage(AttributeTargets.Method)] public class TestCaseOrderAttribute : Attribute { public int Order { get; } public TestCaseOrderAttribute(int order) { Order = order; } } and this is the class level attribute: [AttributeUsage(AttributeTargets.Class)] public class TestClassOrderAttribute : Attribute { public int Order { get; } public TestClassOrderAttribute(int order) { Order = order; } } This is the test case orderer: public class TestCaseOrderer: ITestCaseOrderer { public IEnumerable OrderTestCases(IEnumerable testCases) where TTestCase : ITestCase { return testCases.OrderBy(tc => { var orderAttribute = tc.TestMethod.Method.GetCustomAttributes(typeof(TestCaseOrderAttribute)).FirstOrDefault(); return orderAttribute?.GetNamedArgument("Order") ?? 0; }); } } and this is the class orderer: public class TestCollectionOrderer : ITestCollectionOrderer { public IEnumerable OrderTestCollections(IEnumerable testCollections) { return testCollections.OrderBy(tc => { var classOrderAttribute = tc.CollectionDefinition.GetCustomAttributes(typeof(TestClassOrderAttribute)).FirstOrDefault(); return classOrderAttribute?.GetNamedArgument("Order") ?? 0; }); } } ALL are defined in some infra project in my solution. this is the collection definition - defined in my test project (meaning the attributes and orderers are in a different project): [CollectionDefinition("TestCollection")] public class BasicTestCollectionDefinition: ICollectionFixture { } This is my assemblyInfo of the test project: [assembly: TestCollectionOrderer("Infra.TestOrder.Orderers.TestCollectionOrders.TestCollectionOrderer", "Infra")] [assembly: TestCaseOrderer("Infra.TestOrder.Orderers.TestCaseOrders.TestCaseOrderer", "Infra")] [assembly: CollectionBehavior(DisableTestParallelization = true)] and finally - these are my sample tests: [Collection("TestCollection"), TestClassOrder(2)] [Trait("test_name", "update_installation")] public class PingTest { public PingTest(ILogger logger, LinuxBasicFixture fixture) { Console.WriteLine("Running PingTest linux test"); } [Fact, TestCaseOrder(2)] public void Ping_ShouldSucceed_Second() { Assert.True(true); } [Fact, TestCaseOrder(1)] public void Ping_ShouldSucceed() { Assert.True(true); } } while the ordering of the test cases is working as expected - the class attributes arent found. meaning the line in the test collection orderer var classOrderAttribute = tc.CollectionDefinition.GetCustomAttributes(typeof(TestClassOrderAttribute)).FirstOrDefault(); returns null. The test case attr and orderer and the test collection attr and orderer are written just almost the same as you can see. No matter what i tried and what I read in here and the xUnit docs - i couldnt find what im missing. I looked at this lib (https://github.com/tomaszeman/Xunit.Extensions.Ordering/tree/master) and couldnt find anything im doing different than what its author did - and yet im missing something. I dont want to use the mentioned lib as it is not well maintained. would appreciate any help!