Mlflow not logging metrics returned from custom_eval_function()

So in my config object, I have a customized evaluation function

    "evaluation_num_workers": 1,
    "custom_eval_function": custom_eval_function,

where custom_eval_function is defined simply as

def custom_eval_function(algorithm, eval_workers):
    import mlflow
    mlflow.log_metric('test_metric0', 0)
    return {'test_metric1': 1, 'test_metric2': 2, 'custom_metrics': {'test_metric3': 3}}

However, none of the metrics of test_metric* were logged by mlflow. Is there a way to log the result from evaluation with mlflow? I also added customized metrics in training to 'custom_metrics' in MLflowLoggerCallback and mlflow is able to pick up the customized values.