If you are using an extract, have you tried deleting it and recreating it? To test, i would also link to the same data source in a new workbook and check if i get the same behaviour.
Thanks for your input Vusi. I have solved the problem ....
Please see this extract from the Tableau Server 7 Administration guide (Page 15) which includes
an additional image in the manual. I chose to "Refresh more often" which triggers a refresh when opening the report (causing the Data Update Time to refresh). This of course impacts the report performance so I will look at using "Balanced" as an option once I can determine if it refreshes upon opening of the report.
Views published to Tableau Server are interactive and sometimes have a live connection to a database. As users interact with the views in a web browser, the data that is queried gets
stored in a cache. Subsequent visits will pull the data from this cache if it
is available. The Data Connections tab is where you configure aspects of
caching that will apply to all data connections:
To configure caching, select
from one of the following options: :
• Refresh Less Often—Data is cached and reused whenever it is available regardless of when
it was added to the cache. This option minimizes the number of queries sent to
the database. Select this option when data is not changing frequently.
Refreshing less often may improve performance.
• Balanced—Data is removed from the cache after a specified number of minutes. If the data has
been added to the cache within the specified time range the cached data will be
used, otherwise new data will be queried from the database.
• Refresh More Often—The database is queried each time the page is loaded. The data is
still cached and will be reused until the user reloads the page. This option
will ensure users see the most up to date data; however, it may decrease
Regardless of how caching is configured, the user can click the Refresh button.