DRAFTSIGHT 2017 SP3

I have a drawing set consisting of 4 pages each with a single viewport on the model (that is smaller than the page) and thus 5 tabs in the drawing window (model + 4 page tabs).  In all but one of the page tabs, the window view encompasses the page area outside the viewport boundaries.  In these tabs, I can perform the expected graphical operations (add, delete, modify graphical objects) on the *page* while the page has operations focus. In particular, I have created page titling and guides bound to the page (not model) to manage certain page features during printing. If I double click within the viewport boundaries, then the model (as seen through the given viewport) has operations focus, not the page. Viewport focus is indicated by its boundaries becoming "bold". To change operations focus back the the page, I double click outside the viewport boundaries.  OK, so far so good.

However, I was working in one tab and, not paying close attention, zoomed in while the page had focus such that the viewport boundaries were outside the drawing window, then activated viewport focus to fiddle something in the model. Oops.  Operations focus is now trapped in the viewport - all zoom and scroll and right-click context and menu operations operate on the viewport.  I have not found how to zoom out in *page* space to again access the page area outside the viewport boundaries (to double-click there to get operations focus back to the page) nor found how to deactivate the viewport having operations focus.

I would rather not delete the trapped tab and start over.

Suggestions?  I have to believe the solution is something simple I have not discovered yet.

Windows 10 Pro x64

2 x NVIDIA-driven displays + generic PnP display