[jdbc-v2] Parsing WHEN statement produces error #2723

SELECT
    field1,
    CASE
        WHEN position(field1, 'a') > 0 THEN 'Action1'
        WHEN position(field1, 'b') > 0 THEN 'Action2'
        WHEN
             splitByChar('_', field1)[3] IN ('type1', 'type2')
             AND match(
                 splitByChar('_', field1)[4],
                 '(SUBTYPE1|SUBTYPE2|SUBTYPE3)'
             )
            THEN 'Action3'
        ELSE null
    END AS action_to_do
FROM db.table1

Caused by: java.lang.NullPointerException: Cannot invoke "java.lang.Appendable.append(char)" because "appendable" is null	at 
com.clickhouse.client.api.internal.DataTypeConverter.appendEnquotedArrayElement(DataTypeConverter.java:231)	at 
com.clickhouse.client.api.internal.DataTypeConverter.access$100(DataTypeConverter.java:27)	at 
com.clickhouse.client.api.internal.DataTypeConverter$ListAsStringWriter.onItem(DataTypeConverter.java:290)	at 
com.clickhouse.client.api.internal.BaseCollectionConverter.convert(BaseCollectionConverter.java:63)	at 
com.clickhouse.client.api.internal.DataTypeConverter$ListAsStringWriter.convertAndReset(DataTypeConverter.java:297)	at 
com.clickhouse.client.api.internal.DataTypeConverter.arrayToString(DataTypeConverter.java:205)	at 
com.clickhouse.client.api.internal.DataTypeConverter.convertToString(DataTypeConverter.java:65)	at 
com.clickhouse.client.api.data_formats.internal.AbstractBinaryFormatReader.getString(AbstractBinaryFormatReader.java:333)	at
 com.clickhouse.jdbc.ResultSetImpl.getString(ResultSetImpl.java:267)