diff --git a/src/Infrastructure/BotSharp.Core.Realtime/Services/WaveStreamChannel.cs b/src/Infrastructure/BotSharp.Core.Realtime/Services/WaveStreamChannel.cs
index 8f7767f4..4b194efb 100644
--- a/src/Infrastructure/BotSharp.Core.Realtime/Services/WaveStreamChannel.cs
+++ b/src/Infrastructure/BotSharp.Core.Realtime/Services/WaveStreamChannel.cs
@@ -85,6 +85,7 @@ public class WaveStreamChannel : IStreamChannel
     public void ClearBuffer()
     {
         _bufferedWaveProvider?.ClearBuffer();
+        _audioBufferQueue?.Clear();
     }
 
     private void WaveIn_DataAvailable(object? sender, WaveInEventArgs e)
diff --git a/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Realtime/RealTimeCompletionProvider.cs b/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Realtime/RealTimeCompletionProvider.cs
index b573cc26..f4f3120f 100644
--- a/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Realtime/RealTimeCompletionProvider.cs
+++ b/src/Plugins/BotSharp.Plugin.OpenAI/Providers/Realtime/RealTimeCompletionProvider.cs
@@ -280,7 +280,7 @@ public class RealTimeCompletionProvider : IRealTimeCompletion
         var agent = await agentService.LoadAgent(conn.CurrentAgentId);
         var (prompt, messages, options) = PrepareOptions(agent, []);
 
-        var instruction = messages.FirstOrDefault()?.Content.FirstOrDefault()?.Text ?? agent?.Description;
+        var instruction = messages.FirstOrDefault()?.Content.FirstOrDefault()?.Text ?? agent?.Description ?? string.Empty;
         var functions = options.Tools.Select(x =>
         {
             var fn = new FunctionDef