[JsonIgnore] on interface is ignored on derived type when polymorphic serialization is used

[yohny]

I have an inteface that has [JsonIgnore] attribute on one of its declared properties. I also have a few derived types from it.
The [JsonIgnore] on base interface was respected when serializing until I enabled the polymorphic serialization. Is that by design?

Example:

using System;
using System.Text.Json;
using System.Text.Json.Serialization;
					
public class Program
{	
	//[JsonDerivedType(typeof(Derived))]
	public interface IBase
	{
		public string Question { get; }
		
		[JsonIgnore]
		public int Answer { get; }
	}

	public record Derived : IBase
	{
		public string Question { get; init; }
		public int Answer { get; init; }
	}

	public static void Main()
	{
		var obj = new Derived
		{
			Question = "The ultimate question to life, the universe, and everything",
			Answer = 42
		};
		var serialized = JsonSerializer.Serialize<IBase>(obj);
		Console.WriteLine(serialized); // expected to NOT contain { "Answer ": 42 }
	}
}

While the [JsonDerivedType] is commented out, the Answer propery is not serialized. But once it is uncommented, the property is serialized. Same behaviour is observed when using class instead of record.

fiddle https://dotnetfiddle.net/TNEE6C

Interesting observation - if abstract record/class is used instead of interface, then [JsonIgnore] on base works even with polymorphic serialization enabled.