AS7.2 - JMX Datasource pool & jdbc statistics dissapear if you enable validation

If you just create a basic datasource under AS 7.2 the you can view the current statistics about the pool under

jboss.as:subsystem=datasources,data-source=mySQL,statistics=pool

However, if you add the following then sometimes the statistics=pool and statistics=jdbc entries disspaear

<validation><check-valid-connection-sql>select 1</check-valid-connection-sql></validation>