KAFKA-19652 - Consumer throughput drops by 10 times with Kafka v3.9.0 in ZK mode

Hello Kafka Users and Developers,

For KAFKA-19652 - Consumer throughput drops by 10 times with Kafka v3.9.0
in ZK mode

I wanted to understand if this is a known issue or an isolated edge case.
It was reported back in August 2025 and subsequently confirmed by 2 other
people, able to reproduce the throughput drop. Although nothing
specifically identifying as a blocker for upgrades to this version or later.

Having min.insync.replicas=2 I guess is fairly common, so this would
affect many installations.

Thanks,
Mark