show shards does not show all information expected

show shards does NOT show all the databases nor the tables but only some:

mariadb --user=app --password=secret --host=10.139.158.211 --port=3306 customer_0030 --execute='show shards' | grep customer_00.*1 | column -t
customer_0010. shard1
customer_0010.address shard1
customer_0010.sales shard1
customer_0021. shard2
customer_0021.address shard2
customer_0021.sales shard2
customer_0011. shard1
customer_0011.address shard1
customer_0011.sales shard1

This contradicts IMHO what is written in the docu:
"The schemarouter will also intercept the SHOW DATABASES command and generate it based on its internal data. This means that newly created databases will not show up immediately and will only be visible when the cached data has been updated."
https://mariadb.com/kb/en/mariadb-maxscale-2308-schemarouter/#custom-sql-commands

The missing tables were created long before the MaxScale was restarted last time...