why No new messages seen in ksql even messages exist?

Question

I create table in ksql like this:

CREATE TABLE ORDERS_T (id BIGINT, product VARCHAR, quantity BIGINT, price BIGINT)
  WITH (KAFKA_TOPIC='orders', VALUE_FORMAT='JSON');

In kafka I ve "orders" topic

And when I select query tab in ksql even total messages exists , panel says No new messages like below

So how can I solve this? I want to see results like this example in confluent.io

AND if I do not use EMIT CHANGES it gives this error:

Table 'MYTABLE' is not materialized. Refer to https://cnfl.io/queries for info on query types. If you..

thanks in advance