Long / Integer Serde won't output value - Kafka 3.2

Hello, I am trying something like the word count example and trying to get the value as Long for output. Either to a console or for another consumer application. However, there seems to be an issue with the Long serialization. Basically any version of the word count example I found on GitHub does not seem to work with my current version of Kafka streams / client 3.2.
E.g. this official one from Confluent on Github. The output will only be the key, not the value.

//this below works fine, when using a String to output the number
        ktableoutput.toStream().mapValues(v -> v.toString() + " additional information").to("testoutput", Produced.with(Serdes.String(), Serdes.String()));

//ideally, this should output the Long Number directly, however DOES NOT WORK
        ktableoutput.toStream().to("testoutput", Produced.with(Serdes.String(), Serdes.Long()));

I did try numerous variations (e.g. using Integer) but to no avail.

Using the following relevant config below (also tried it with getName() or without put. )

       props.put(StreamsConfig.DEFAULT_KEY_SERDE_CLASS_CONFIG, Serdes.String().getClass());
       props.put(StreamsConfig.DEFAULT_VALUE_SERDE_CLASS_CONFIG, Serdes.String().getClass());

So it’s very strange. It seem to not work with any usage of numbers, but works fine when converted to a String.

When you say it does not work, what do you observe? Is anything crashing? Are there exceptions? – What command to do you use to read the data?