Old datasets don't "see" Gateway but new datasets ...

We have several previously created dashboards in which the datasets were refreshed manually on the desktop and published, data is using a development database. We have since created a data source to development on our gateway. New dashboards created after the data source creation can "see" the gateway and schedule refreshes of datasets but any dashboard created prior to the new data source do not "see" the gateway it is grayed out. We have attempted several remedies, deleting dashboard and republishing, renaming the dashboard, and addding a new source to the existing dashboard and republishing but all with the same results. Any suggestions or similar experience?

patw