Issue with corrupted assets flutter, fastapi, Lambda, ApiGateway, S3

I'm running into a strange issue with the following setup:

Flutter app that uploads an image to a fastapi backend thats served from a lambda function through ApiGateway, which uses bota3 to upload and serve the image from s3.

My python routes look like this.

@router.get("{filePath:path}")
async def read_root(filePath, current_user: CognitoClaims = Depends(get_current_user)):
    user: User = await get_user(current_user.username)
    company: Company = await get_company(user);

    try:
        response = s3.generate_presigned_url('get_object', Params={
            'Bucket': settings.s3_bucket,
            'Key': filePath.strip("/")
        }, ExpiresIn=3600)
    except ClientError as e:
        logging.error(e)
        return None
    return response

@router.post("")
async def add_file(current_user: CognitoClaims = Depends(get_current_user), file: UploadFile = File(...)):
    user: User = await get_user(current_user.username)
    company: Company = await get_company(user);

    file_name = file.filename;

    full_name = f"{current_user.username}/uploads/{file_name}"

    try:
        s3.upload_fileobj(file.file, settings.s3_bucket, full_name)
    
        response = s3.generate_presigned_url('get_object', Params={
                'Bucket': settings.s3_bucket,
                'Key': full_name
            }, ExpiresIn=3600);
    except ClientError as e:
        logging.error(e)
        return None
        
    return {
        "path": full_name,
        'url': response
    };

The endpoints and functions are all successful, but the images uploaded to s3 seem to be corrupted.

The strange part is that I am able to use these endpoints perfectly when hitting using postman, and even stranger than that it runs fine locally from the flutter app. so i can only assume its an issue related to my ApiGateway setup.