We are getting errors with "unsupported protocol version" from Cassandra.
This is happening more in high-load condition.
We are using driver 4.2.1 and we tried with setting the protocol version explicitly to 4 as well.
We also tried not setting the protocol and letting the driver negotiate with the cluster. In both cases its the same error that's happening.
What is even more confusing is how the version is getting set to 15, 69 etc.