self referencing serialization ignored

Models/Account.cs

@@ -4,6 +4,7 @@ using System;
 using System.Collections.Generic;
 using System.ComponentModel.DataAnnotations.Schema;
 using System.Reflection;
+using System.Text.Json.Serialization;
 using System.Threading.Tasks;
 
 public class Account
@@ -27,5 +28,6 @@ public class Account
     public bool IsBot { get; set; } //webhook counts
     public Channel SeenInChannel { get; set; }
     public string Protocol { get; set; }
+    [JsonIgnore]
     public User IsUser {get; set;}
 }

Models/Channel.cs

@@ -7,6 +7,7 @@ using System.Reflection;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Components.Web;
 using Microsoft.EntityFrameworkCore;
+using Newtonsoft.Json;
 using static vassago.Models.Enumerations;
 
 public class Channel
@@ -17,6 +18,7 @@ public class Channel
     public string DisplayName { get; set; }
     [DeleteBehavior(DeleteBehavior.Cascade)]
     public List<Channel> SubChannels { get; set; }
+    [JsonIgnore]
     public Channel ParentChannel { get; set; }
     public string Protocol { get; set; }
     [DeleteBehavior(DeleteBehavior.Cascade)]
@@ -82,6 +84,23 @@ public class Channel
             }
         }
     }
+
+    ///<summary>
+    ///break self-referencing loops for library-agnostic serialization
+    ///</summary>
+    public Channel AsSerializable()
+    {
+        var toReturn = this.MemberwiseClone() as Channel;
+        toReturn.ParentChannel = null;
+        if(toReturn.Users?.Count > 0)
+        {
+            foreach (var account in toReturn.Users)
+            {
+                account.SeenInChannel = null;
+            }
+        }
+        return toReturn;
+    }
 }
 
 public class DefinitePermissionSettings

Program.cs

@@ -11,7 +11,10 @@ var builder = WebApplication.CreateBuilder(args);
 builder.Services.AddControllersWithViews();
 builder.Services.AddSingleton<IHostedService, vassago.ConsoleService>();
 builder.Services.AddDbContext<ChattingContext>();
-builder.Services.AddControllers().AddNewtonsoftJson();
+builder.Services.AddControllers().AddNewtonsoftJson(options => {
+        options.SerializerSettings.ReferenceLoopHandling =
+            Newtonsoft.Json.ReferenceLoopHandling.Ignore;
+    });
 builder.Services.AddProblemDetails();
 builder.Services.Configure<RazorViewEngineOptions>(o => {
     o.ViewLocationFormats.Clear();

WebInterface/Controllers/api/ChannelsControler.cs

@@ -33,6 +33,10 @@ public class ChannelsController : ControllerBase
 		{
 			_logger.LogError($"attempt to update channel {channel.Id}, not found");
 			return NotFound();
+        }
+        else
+        {
+            _logger.LogDebug($"patching {channel.DisplayName} (id: {channel.Id})");
         }
 		//settable values: lewdness filter level, meanness filter level. maybe i could decorate them... 
 		fromDb.LewdnessFilterLevel = channel.LewdnessFilterLevel;