Hello, yes, this is a feature. Simply press F5 whilst in the viewing section and it’ll change it to full screen.
So you want to press F5 on this screen:
Then it should go into fullscreen. Make sure you’re using the latest version which is 6.1.0
Note: F5 is the “function 5” button, not F+5
Here is a picture to show you the buttons, press the one that says “F5” their usually the same on most keyboards, sometimes their separated.