Kafka streams - message not materialized in intermediate topics

Hello Kafka team,

I am seeing an odd behavior when using kafka streams.

During periods of heavier volumes, there are messages coming in. However,
they do look like they are processed by the adder/subtractor and are not
materialized in the intermediate topics which causes them not to be
outputted in the final topic.

Is there any way to debug this or log out when a message is dropped in the
stream and not processed for whatever reason?

Thanks,

Tomer