CS8602/CS8604 odd behaviour flagging in unit tests despite null assertion.

[StevePy]

For example the following code:

Assert.That(given.CapturedPaginationViewModel, Is.Not.Null);
Assert.That(given.CapturedPaginationViewModel.CurrentPage, Is.EqualTo(1)); // <- CS8602
Assert.That(given.CapturedPaginationViewModel.PageSize, Is.EqualTo(5));
Assert.That(given.CapturedPaginationViewModel.TotalRecords, Is.EqualTo(1));

where "given" is a BDD-style wrapper for the test:

private class Given : BaseGiven
{
    // ...
    public PaginationViewModel? CapturedPaginationViewModel { get; private set; } = default;
    // ...
}

The 2nd line, and only the 2nd line is getting flagged with a CS8602. With a .Net Core 8 build this warning did not appear, it seemed to pick up the Is.Not.Null assertion and was satisfied with that. What is quite unusual is that if I add a null forgiveness "!" to the second line, the warning does not migrate to the 3rd or 4th lines, they do not produce the CS8602 warning.

CurrentPage, PageSize, and TotalRecords are all int properties of the view model. I don't like the idea of slapping null forgiveness bangs in my unit tests, and I do not like having builds littered with warnings to ignore. Adding bangs to the unit tests is a lesser evil but I wanted to raise this just to determine if this is a unexpected issue that can be fixed, or is there a better way to test scenarios like this. (Assert.Multiple had no impact on the warning)