kSQLDB: Key format: does not match any supported format with a structured key (AVRO FORMAT)

Question

ERROR:

     ksql> print 'locator.key' FROM BEGINNING LIMIT 1;
            Key format:  does not match any supported format. It may be a STRING with encoding other than UTF8, or some other format.
            ...
            key: \x00\x00\x00\x00\x94\x02\x1C10.10.10.10\x02Pff6204b2f1bf11eda05b0242ac120003, ...

I have a KSQL stream ip_locator that reads data from a Kafka topic an input stream (not our concern here) and selects two fields (ip and uaid) from the geolocation and user nested structures, respectively. This stream works fine and emits AVRO-formatted.

 CREATE STREAM ip_locator
                WITH (VALUE_FORMAT='AVRO', KEY_FORMAT='KAFKA', KAFKA_TOPIC='locator',PARTITIONS=4, REPLICAS=4) AS
                SELECT 
                    geolocation->ip as ip,
                    user->uaid as uaid
                FROM input
                EMIT CHANGES;

        ksql>  print 'locator' FROM BEGINNING LIMIT 1;
        Key format: ¯\_(ツ)_/¯ - no data processed
        Value format: AVRO
        rowtime: 2022/04/4 11:13:33.131 Z, key: <null>, value: {"IP": "10.10.10.10", "UAID": "ff6204b2f1bf11eda05b0242ac120003"}, partition: 3
        Topic printing ceased

Now I want to create a new stream ip_key that uses the same data from ip_locator but sets the Kafka topic key as a composite structure with the ip and uaid fields. For this, I use the STRUCT function to build the key.

CREATE STREAM ip_key
            WITH (FORMAT='AVRO', KAFKA_TOPIC='locator.key', PARTITIONS=4,REPLICAS=4) AS
            SELECT 
                STRUCT("ip":= ip, "uaid" := uaid) KEY,
                AS_VALUE(ip) as IP,
                AS_VALUE(uaid) as uaid,
            FROM ip_locator
            PARTITION BY STRUCT("ip":= ip, "uaid" := uaid)
            EMIT CHANGES;

However, when I try to print the Kafka topic locator.key that corresponds to the new stream, I get an error message saying that the key format is not recognized

  ksql> print 'locator.key' FROM BEGINNING LIMIT 3;
            Key format:  does not match any supported format. It may be a STRING with encoding other than UTF8, or some other format.
            Value format: AVRO
            rowtime: 2022/04/4 11:13:33.131 Z, key: \x00\x00\x00\x00\x94\x02\x1C10.10.10.10\x02Pff6204b2f1bf11eda05b0242ac120003, value: {"IP": "10.10.10.10", "UAID": "ff6204b2f1bf11eda05b0242ac120003"}, partition: 3
            Topic printing ceased

Thank you for the help.

I was expecting the key to have the following format:

key: {"IP": "10.10.10.10", "UAID": "ff6204b2f1bf11eda05b0242ac120003"}