Bug: Kafka consumer lag

[alteest]

Describe the bug
Use consumer to get data from Kafka and it's read not all data. It goes to zero and then grows up to ~4k (I suppose it depend on messages).

How to reproduce
Simple kafka broker and consumer

broker = KafkaBroker(
    settings.KAFKA_BOOTSTRAP,
    security=SASLPlaintext(
        username=settings.KAFKA_USER,
        password=settings.KAFKA_PASSWORD,
        use_ssl=False
    ),
    max_request_size=settings.KAFKA_MAX_REQUEST_SIZE,
    graceful_timeout=settings.KAFKA_GRACEFUL_TIMEOUT,
    logger=None,
    validate=False
)

subscriber = broker.subscriber(
    *settings.KAFKA_TOPICS, group_id=settings.KAFKA_GROUP,
    batch=True, max_records=settings.KAFKA_MAX_RECORDS
)

Expected behavior
I want to see minum consumer lag

Observed behavior
See on screenshots and what is strange it's related to uphills on 'Message consume per minute'

Screenshots

Environment
faststream[cli,confluent]==0.5.23