Kafka producer message ordering problem?

[xirikiri]

Hello, i have a producer with max.in.flight.requests.per.connection = 1 and a message key to keep the order of messages in partition. But sometimes on a large data flow, very rarely the order in the partition is broken. I am using 2.8.11 version.
Does Kafka really guarantee order or not? Maybe some race condition when checking active in-flight-batches?

Maybe there are experts here who have encountered this problem?)
My config:

        acks = -1
	auto.include.jmx.reporter = true
	batch.size = 16384
        buffer.memory = 33554432
	client.dns.lookup = use_all_dns_ips
	client.id = producer-1
	compression.gzip.level = -1
	compression.lz4.level = 9
	compression.type = none
	compression.zstd.level = 3
	connections.max.idle.ms = 540000
	delivery.timeout.ms = 120000
	enable.idempotence = true
	enable.metrics.push = true
	interceptor.classes = []
	key.serializer = class org.apache.kafka.common.serialization.StringSerializer
	linger.ms = 0
	max.block.ms = 60000
	max.in.flight.requests.per.connection = 1
	max.request.size = 1048576
	metadata.max.age.ms = 300000
	metadata.max.idle.ms = 300000
	metadata.recovery.strategy = none
	metric.reporters = []
	metrics.num.samples = 2
	metrics.recording.level = INFO
	metrics.sample.window.ms = 30000
	partitioner.adaptive.partitioning.enable = true
	partitioner.availability.timeout.ms = 0
	partitioner.class = null
	partitioner.ignore.keys = false
	receive.buffer.bytes = 32768
	reconnect.backoff.max.ms = 1000
	reconnect.backoff.ms = 50
	request.timeout.ms = 30000
	retries = 2147483647
	retry.backoff.max.ms = 1000
	retry.backoff.ms = 100
	sasl.client.callback.handler.class = null
	sasl.jaas.config = [hidden]
	sasl.kerberos.kinit.cmd = /usr/bin/kinit
	sasl.kerberos.min.time.before.relogin = 60000
	sasl.kerberos.service.name = null
	sasl.kerberos.ticket.renew.jitter = 0.05
	sasl.kerberos.ticket.renew.window.factor = 0.8
	sasl.login.callback.handler.class = null
	sasl.login.class = null
	sasl.login.connect.timeout.ms = null
	sasl.login.read.timeout.ms = null
	sasl.login.refresh.buffer.seconds = 300
	sasl.login.refresh.min.period.seconds = 60
	sasl.login.refresh.window.factor = 0.8
	sasl.login.refresh.window.jitter = 0.05
	sasl.login.retry.backoff.max.ms = 10000
	sasl.login.retry.backoff.ms = 100
	sasl.mechanism = SCRAM-SHA-512
	sasl.oauthbearer.clock.skew.seconds = 30
	sasl.oauthbearer.expected.audience = null
	sasl.oauthbearer.expected.issuer = null
	sasl.oauthbearer.jwks.endpoint.refresh.ms = 3600000
	sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms = 10000
	sasl.oauthbearer.jwks.endpoint.retry.backoff.ms = 100
	sasl.oauthbearer.jwks.endpoint.url = null
	sasl.oauthbearer.scope.claim.name = scope
	sasl.oauthbearer.sub.claim.name = sub
	sasl.oauthbearer.token.endpoint.url = null
	security.protocol = SASL_SSL
	security.providers = null
	send.buffer.bytes = 131072
	socket.connection.setup.timeout.max.ms = 30000
	socket.connection.setup.timeout.ms = 10000
	ssl.cipher.suites = null
	ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
	ssl.endpoint.identification.algorithm = https
	ssl.engine.factory.class = null
	ssl.key.password = null
	ssl.keymanager.algorithm = SunX509
	ssl.keystore.certificate.chain = null
	ssl.keystore.key = null
	ssl.keystore.location = null
	ssl.keystore.password = null
	ssl.keystore.type = JKS
	ssl.protocol = TLSv1.3
	ssl.provider = null
	ssl.secure.random.implementation = null
	ssl.trustmanager.algorithm = PKIX
	ssl.truststore.certificates = null
	ssl.truststore.location = null
	ssl.truststore.password = null
	ssl.truststore.type = JKS
	transaction.timeout.ms = 60000
	transactional.id = null
	value.serializer = class org.springframework.kafka.support.serializer.DelegatingByTopicSerializer