Enter the diagram editor from page view via the pencil icon. Since version 2.0.0 of the DMN Modeler Enterprise, you see a message flag in the upper right corner, that offers to publish this version now, if it is in draft mode. Click this link, and the latest diagram version will be publish on the page, i.e. visible in view page mode.
Note that this message only appears, if you entered the diagram editor from page view. It will not show if you entered from page editor. In this case, you may publish the page to publish the latest diagram version.