CorelDraw 2021 - Welcome screen will not shut down and a grey screen

When  I start CorelDRAW 2021, the "Welcome screen" will not go away once I've either opened a document or clicked the plus sign for a New Document. 
The program will open a file, and I can see that it's open on the bar on the top left but I can't see anything on the screen other than the welcome screen.
If I click the X for the welcome screen, the Welcome screen goes, - BUT, then I am left with a blank grey screen, even though the tab shows that my file is open on the information bar at the top - BUT! I cannot  see anything on my work area other than a big grey nothingness and I cannot work with anything. Has this happened to anyone else please?

Turning off the X for welcome screen gets that to go away, but I still don't see my page once, just and only a big grey area. However, really strange... If I open a file, whilst I cannot see it on main work screen, if I go to “Print Preview”, I can see see it - and then, when I close print preview, my file is actually visible in the work are but frozen, I cannot do anything with - the only thing I can do is close down CorelDraw. This all means that I have CorelDraw that is simply unusable, it is nothing more than a picture on my screen that I can do nothing with. Does anyone know how to solve this please?