ReSharper not supporting Assert.That - unit-testing

Question

I'm in the process of returning to ReSharper recently, using trial of the newest version - 2022.2.3. I've got quite surprised when one of my nUnit tests failed in a weird way, when run by Resharper's built in Unit Test runner. Something that has never happened to me with a Test Explorer.
As long as the Asserts pass, it's all fine - green, all tests are listed. However, when the assert fails, it says One or more child tests had errors. Exception doesn't have a stacktrace
Not only there is no mention of actual values that weren't correct, but the whole failing test seems to be gone!
This happens only when I use the 'modern' approach with Assert.That. So
Assert.That(httpContext.Response.StatusCode, Is.EqualTo(200));
is causing issues, meanwhile, the more classic:
Assert.AreEqual(200, httpContext.Response.StatusCode);
works as expected. Is that something that is a known bug, or maybe some attributes are required? JetBrains claims they have full support of nUnit out of the box, so that is a bit surprising.
NOTE: the tests methods are async, awaiting result and returning Tasks, beside this nothing unusual.
EDIT: The test code is as follows, ApiKeyMiddleware is any middleware that returns response with 200 here.
[TestFixture]
public class ApiKeyMiddlewareTests
{
[Test]
public async Task Invoke_ActiveKey_Authorized()
{
var httpContext = new DefaultHttpContext();
httpContext.Request.Headers.Add("XXXXX", "xxxx");
var configuration = Options.Create(new AccessConfiguration { ActiveApiKeys = new List<string> { "xxxx" } });
var middleware = new ApiKeyMiddleware(GetEmptyRequest(), configuration);
await middleware.Invoke(httpContext);
Assert.That(httpContext.Response.StatusCode, Is.EqualTo(200)); //change to anything else than 200 and it fails + vanishes
}
}