Kafka, MutinyEmitter.sendAndAwait context propagation issue

[mapuci]

I have created issue on quarkus git repo, but I found no one brave enough to face it :)
quarkusio/quarkus#39098 (reproducer link is at the bottom)

The issue is: when using any kind of emitter to send message to kafka in a blocking manner (using regular blocking JTA @ Transactional) the transaction will sometimes still be bound to 2 threads kafka-producer-network-thread and regular executor thread in time of commit (on executor thread ofc.). This causes TX to fail, in a dramatic way. It happens randomly, chance is like 1:1000.

2024-03-01 08:32:55,162 WARN  [com.arj.ats.arjuna] (executor-thread-2) ARJUNA012094: Commit of action id 0:ffff0a010a48:e441:65e18477:d1d0 invoked while multiple threads active within it.
2024-03-01 08:32:55,163 WARN  [com.arj.ats.arjuna] (executor-thread-2) ARJUNA012107: CheckedAction::check - atomic action 0:ffff0a010a48:e441:65e18477:d1d0 commiting with 2 threads active!
2024-03-01 08:32:55,163 WARN  [com.arj.ats.jta] (executor-thread-2) ARJUNA016039: onePhaseCommit on < formatId=131077, gtrid_length=35, bqual_length=36, tx_uid=0:ffff0a010a48:e441:65e18477:d1d0, node_name=quarkus, branch_uid=0:ffff0a010a48:e441:65e18477:d1d3, subordinatenodename=null, eis_name=0 > (io.agroal.narayana.LocalXAResource@2ea67dc) failed with exception XAException.XA_RBROLLBACK: javax.transaction.xa.XAException: Error trying to transactionCommit local transaction: Enlisted connection used without active transaction

The issue is that executor thread is blocked until message gets ACKed. But this is done BEFORE contextPropagation clears propagated contexts on kafka-producer-network-thread. So it is kind of race condition I guess.
Problem can be bypassed using different thread when sending to kafka, thread without TX context propagation. e.g. @ManagedExecutorConfig(cleared = ThreadContext.TRANSACTION)

Quarkus reproducer:

• https://github.com/MatejPucihar/kafka-db-tx
• reproducer stress tests the app, since the chance of EX is low, I have no other idea, how to reproduce it.
• EX is reproduced for both MutinyEmitter and regular Emitter.

That are all the insights I can provide :) I'm for sure not an expert with reactive or context propagation, so take my insights with a grain of salt. The reproducer is real.
If this is not a bug, it would at least deserve some honorable mention in quarkus documentation I guess.