.Net: Bug: gemini-1.5-flash function calling is not working getting 400 bad request error.

[PraveenVerma17]

Describe the bug
kernel function call is not working properly with gemini-1.5-flash for below code

using Microsoft.SemanticKernel;
using Microsoft.SemanticKernel.ChatCompletion;
using Microsoft.SemanticKernel.Connectors.Google;
using SementicKernelDemo.Plugins.LightsPlugin;



string? modelID = Environment.GetEnvironmentVariable("MODEL_ID");
string? apiKey = Environment.GetEnvironmentVariable("API_KEY");

if (string.IsNullOrEmpty(modelID) || string.IsNullOrEmpty(apiKey))
    throw new Exception("Please set the MODEL_ID and API_KEY environment variables to your Google AI Gemini model ID and API key, respectively.");

// create kernel
#pragma warning disable SKEXP0070 
var kernel = Kernel.CreateBuilder()
                    .AddGoogleAIGeminiChatCompletion(modelID, apiKey, GoogleAIVersion.V1)
                    .Build();



// Add plugins
kernel.Plugins.AddFromType<LightsPlugin>("Lights");


//Enable Prompt Execution Settings 
GeminiPromptExecutionSettings geminiPromptExecutionSettings = new() {
    FunctionChoiceBehavior = FunctionChoiceBehavior.Auto(),
    ToolCallBehavior = GeminiToolCallBehavior.EnableKernelFunctions
};



var chatCompletionService = kernel.GetRequiredService<IChatCompletionService>();
var history = new ChatHistory();

string? userInput;
do
{
    Console.WriteLine("User >");
    userInput = Console.ReadLine();
    try
    {
        history.AddUserMessage(userInput);
        var result = await chatCompletionService.GetChatMessageContentAsync(
            history,
            executionSettings: geminiPromptExecutionSettings,
            kernel: kernel);

        Console.WriteLine("Assistant > " + result);
        history.AddMessage(result.Role, result.Content ?? string.Empty);
    }
    catch (Exception ex)
    {
        Console.WriteLine("Error: " + ex.Message);
    }
} while (userInput is not null);


#pragma warning restore SKEXP0070

To Reproduce
Steps to reproduce the behavior:
Execute the above code its failing when ToolCallBehavior = GeminiToolCallBehavior.EnableKernelFunctions or ToolCallBehavior = GeminiToolCallBehavior.AutoInvokeKernelFunctions is set. if i don't set it does not recognize kernel functions.

Expected behavior
It should recognize kernel functions and return the result back from my plugin

Screenshots

Platform

• OS: Windows
• IDE: Visual Studio
• Language: C#
• Source: microsoft.sementic.kernel and connector.google

Additional context