EF inMemory provider falsely accepting null entries when the fields are set to required

Here is my integration test code:

[Fact(DisplayName = "Should only add AssetType when Name Provided")]
public async Task Test4()
{
    using (var context = GetContext()) {

        var listAssetTypes = await context.AssetType.ToListAsync();

        Assert.Equal(0, listAssetTypes.Count);

        var goodAssetType = new AssetType { Name = "1st Item" };
        context.Add(goodAssetType);
        await context.SaveChangesAsync();
        listAssetTypes = await context.AssetType.ToListAsync();

        Assert.Equal(1, listAssetTypes.Count);

        var badAssetType = new AssetType {};
        context.Add(badAssetType);
        await context.SaveChangesAsync();
        listAssetTypes = await context.AssetType.ToListAsync();

        Assert.Equal(1, listAssetTypes.Count);
    }
}

The first two assert's pass. The 3rd fails, Actual is 2, and if I debug I can see a new Id has been assigned and the name is set to null.

Here is my context method:

private WorldContext GetContext()
{
    var builder = new ConfigurationBuilder();
    var config = builder.Build();
    var options = new DbContextOptionsBuilder<WorldContext>()
        .UseInMemoryDatabase(Guid.NewGuid().ToString()).Options;
    var context = new WorldContext(config, options);
    return context;
}

And my model:

public class AssetType
{
    [DatabaseGenerated(databaseGeneratedOption: DatabaseGeneratedOption.Identity)]
    [Key]
    public int AssetTypeId { get; set; }
    [Required]
    public string Name { get; set; }
}