Solved VMSP 15, un-docked Preview Screen does not expand to full screen size, why?

When I wish to preview a project in almost-full screen mode in Vegas MSP 15, during the edit or just prior to render, I un-dock it by grabbing the Video Preview screen tab and dragging it to my second screen. However, it only appears as a narrow strip (see attached) and not a full screen as desired.

I have tried various settings in preferences without success. I can double-tap the Video Preview screen frame and the screen will increase in size just a little bit, or decrease but never to the full screen. I have to manually drag out the corners.

I've tried this with Preview (Auto), Preview (Full), Best (Full) with the same results.

Am I missing something, is there a method that I have not tried?

The first thing I would say is why don't you just preview your project Full Screen on your 2nd Monitor ?
This is the easiest solution and what most people would do with 2 monitors.

All you have to do is press the Video Preview button above the main preview window.
This opens your Preview Window full screen on the 2nd monitor.
If it does not do this by default, check your Preview Window settings and identify/set your monitors.





If you don't want to do that and stick with your current method, you can create and save a Custom Window Layout.
The first thing I would do is default your main layout.
Go to View/Window Layouts/Default Layout

Now drag the bottom tab of the Preview Window onto your 2nd monitor.
Resize window by dragging bottom right corner of Preview Window.
Then go to View/Window Layout/Save Layout As
Name and save this new custom window layout.

Go back to View/Window Layout/Default Layout - when you want to restore the User Interface.

Using the first method at top of this message is easiest solution.

Both suggestions are excellent, Derek.

I generally prefer the 2nd option as I can keep the preview screen very close to my actions on the timeline while editing. Then when I wish to preview the draft I can drag the preview screen out.

I will do as you say, manually resize it and save for future use. Interestingly, I think I had the same issue with VMSP 14, dragged it to the desired full size and thereafter, when un-docked, it was always at that full size. But maybe my memory is flawed, maybe I did set the custom setting and saved?

I will happily try your 1st option as well, maybe I should break my habits and vary how it is done.

By the way, I have a few other issues with VMSP 15, will address them separately. To do with rendering 480p and 360p when needing a small file to attach to email for phone or tablet. More anon.

Thank you, Derek.

Today, Thursday, is my first opportunity to test your first option, Derek, the external monitor. It worked without any adjustments required.
I feel foolish to have missed that, hidden in plain view! Solved, thank you.