diff --git a/dotnet/AipsRT/Hubs/WhiteboardHub.cs b/dotnet/AipsRT/Hubs/WhiteboardHub.cs
index a94589c..519c915 100644
--- a/dotnet/AipsRT/Hubs/WhiteboardHub.cs
+++ b/dotnet/AipsRT/Hubs/WhiteboardHub.cs
@@ -21,12 +21,14 @@ public class WhiteboardHub : Hub
     private readonly WhiteboardManager _whiteboardManager;
     private readonly IMessagingService _messagingService;
     private readonly MembershipService _membershipService;
+    private readonly GetUserService _getUserService;
 
-    public WhiteboardHub(WhiteboardManager whiteboardManager, IMessagingService messagingService, MembershipService membershipService)
+    public WhiteboardHub(WhiteboardManager whiteboardManager, IMessagingService messagingService, MembershipService membershipService, GetUserService getUserService)
     {
         _whiteboardManager = whiteboardManager;
         _messagingService = messagingService;
         _membershipService = membershipService;
+        _getUserService = getUserService;
     }
 
     public override async Task OnDisconnectedAsync(Exception? exception)
@@ -71,9 +73,10 @@ public class WhiteboardHub : Hub
             status = await _membershipService.GetMembershipStatus(whiteboardId, userId);
         }
         
+        _whiteboardManager.AddUserToWhiteboard(userId, whiteboardId);
+        
         if (status == WhiteboardMembershipStatus.Accepted)
         {
-            _whiteboardManager.AddUserToWhiteboard(userId, whiteboardId);
 
             var joiningUser = whiteboard.Users.FirstOrDefault(u => u.UserId == userId);
             if (joiningUser == null)
@@ -84,8 +87,7 @@ public class WhiteboardHub : Hub
                 }
                 else
                 {
-                    joiningUser = new User(userId, Context.User?.Identity?.Name ?? "Unknown",
-                        "");
+                    joiningUser = new User(userId, Context.User?.Identity?.Name ?? "Unknown", "");
                     whiteboard.AddUser(joiningUser);
                 }
             }
@@ -101,7 +103,12 @@ public class WhiteboardHub : Hub
         {
             await Clients.Caller.SendAsync("WaitingForApproval", userId.ToString());
             
-            var user = whiteboard.Users.First(u => u.UserId == userId);
+            var user = whiteboard.Users.FirstOrDefault(u => u.UserId == userId);
+            
+            if (user == null)
+            {
+                user = await _getUserService.GetUser(userId);
+            }
 
             await Clients.User(ownerId.ToString()).SendAsync("UserWaitingForApproval", user);
         }
@@ -113,8 +120,15 @@ public class WhiteboardHub : Hub
 
         await _messagingService.AcceptedUser(new AcceptUserRequestToJoinCommand(whiteboard.WhiteboardId.ToString(), targetUserId.ToString()));
         
+        var user = whiteboard.Users.FirstOrDefault(u => u.UserId == targetUserId);
+        
+        whiteboard.AddActiveUser(user!);
+        
         await Clients.User(targetUserId.ToString()).SendAsync("Accepted");
         await Clients.User(targetUserId.ToString()).SendAsync("InitWhiteboard", whiteboard);
+
+        await Clients.GroupExcept(whiteboard.WhiteboardId.ToString(),
+            Context.ConnectionId).SendAsync("Joined", user);
     }
     
     public async Task RejectUser(Guid targetUserId)
diff --git a/dotnet/AipsRT/Model/Users/GetUserService.cs b/dotnet/AipsRT/Model/Users/GetUserService.cs
new file mode 100644
index 0000000..988939e
--- /dev/null
+++ b/dotnet/AipsRT/Model/Users/GetUserService.cs
@@ -0,0 +1,22 @@
+using AipsCore.Application.Abstract;
+using AipsCore.Application.Models.User.Query.GetUser;
+
+namespace AipsRT.Model.Users;
+
+public class GetUserService
+{
+    private readonly IDispatcher _dispatcher;
+    
+    public GetUserService(IDispatcher dispatcher)
+    {
+        _dispatcher = dispatcher;
+    }
+
+    public async Task<User> GetUser(Guid userId)
+    {
+        var query = new GetUserQuery(userId.ToString());
+        var userQueryDto = await _dispatcher.Execute(query);
+        
+        return new User(Guid.Parse(userQueryDto.Id), userQueryDto.UserName, userQueryDto.Email);
+    }
+}
\ No newline at end of file
diff --git a/dotnet/AipsRT/Program.cs b/dotnet/AipsRT/Program.cs
index 8d0d68e..8d8125e 100644
--- a/dotnet/AipsRT/Program.cs
+++ b/dotnet/AipsRT/Program.cs
@@ -2,6 +2,7 @@ using AipsCore.Application.Common.Message.ErrorMessage;
 using AipsCore.Infrastructure.DI;
 using AipsRT.Hubs;
 using AipsRT.Model.Memberships;
+using AipsRT.Model.Users;
 using AipsRT.Model.Whiteboard;
 using AipsRT.Services;
 using AipsRT.Services.Interfaces;
@@ -23,6 +24,7 @@ builder.Services.AddSingleton<IErrorMessageHandleStrategy, RtErrorHandleStrategy
 builder.Services.AddHostedService<ErrorSubscriberBackgroundService>();
 
 builder.Services.AddTransient<MembershipService>();
+builder.Services.AddTransient<GetUserService>();
 
 builder.Services.AddScoped<GetWhiteboardService>();
 builder.Services.AddSingleton<WhiteboardManager>();
diff --git a/front/src/stores/whiteboard.ts b/front/src/stores/whiteboard.ts
index 2fab846..c3eb8a4 100644
--- a/front/src/stores/whiteboard.ts
+++ b/front/src/stores/whiteboard.ts
@@ -51,11 +51,21 @@ export const useWhiteboardStore = defineStore('whiteboard', () => {
   }
 
   function registerHubEvents() {
+    whiteboardHubService.offAll()
+
     whiteboardHubService.onInitWhiteboard((wb) => {
       console.log('InitWhiteboard payload:', JSON.stringify(wb, null, 2))
       deselectShape()
+
       whiteboard.value = wb
-      connectedUsers.value = wb.activeUsers ?? []
+
+      const uniqueUsers = new Map()
+
+      for (const user of wb.activeUsers ?? []) {
+        uniqueUsers.set(user.userId, user)
+      }
+
+      connectedUsers.value = Array.from(uniqueUsers.values())
       isLoading.value = false
     })
 
@@ -95,7 +105,7 @@ export const useWhiteboardStore = defineStore('whiteboard', () => {
     })
 
     whiteboardHubService.onUserWaitingForApproval((user) => {
-      if (!pendingUsers.value.includes(user)) {
+      if (!pendingUsers.value.some(u => u.userId === user.userId)) {
         pendingUsers.value.push(user)
       }
     })
diff --git a/front/src/stores/whiteboards.ts b/front/src/stores/whiteboards.ts
index 9422eab..fbdb553 100644
--- a/front/src/stores/whiteboards.ts
+++ b/front/src/stores/whiteboards.ts
@@ -2,7 +2,7 @@ import { defineStore } from 'pinia'
 import { ref } from 'vue'
 import type {JoinResult, Whiteboard} from '@/types'
 import { whiteboardService } from '@/services/whiteboardService'
-import type {WhiteboardJoinPolicy} from "@/enums";      
+import type {WhiteboardJoinPolicy} from "@/enums";
 
 export const useWhiteboardsStore = defineStore('whiteboards', () => {
   const ownedWhiteboards = ref<Whiteboard[]>([])