I am using aws lex StartConversation API with the built-in intent called 'BedrockAgentIntent' so the bot uses a created bedrock agent to answer user requests, it is working from the console, but when I do it through the SDK, I get this error:

Invalid Bot Configuration: Amazon Lex could not access your Amazon Bedrock Agent. There is a problem with your config urationFailed to validate request sent to Bedrock Agent

Note that, within the conversation:

• When I send TEXT the bot answers, whether from the agent intent, or any other intent that has predefined responses.
• When I send AUDIO and I have another intent with pre-defined responses, the intent gets invoked and the bot answers.
• When I send AUDIO and I am just having the BedrockAgentIntent, the error occurs

I've attached the 'AmazonBedrockFullAccess' policy to the Lex's execution role, but still the error persists, so I think this is not a permission issue.