There are some cases where users experience blank sidebars and even moved elements. These are display errors that can be fixed with a few configurations.

Step-by-Step Guide:

1. Activate the compatibility mode in Office. 
   Navigate to the "File" tab
   
   
   
    
2. Click on "Options"
   
   
3. Activate the compatibility mode by clicking on "Optimize for compatibility".
   
   
   
    
4. After you have activated the compatibility mode, you should close PowerPoint.
   
   
    
5. Now you should change your screen resolution to the resolution your screen has natively. To do this, right-click on the desktop and navigate to the "Display settings".
   
   
   
   
    
6. Now you can change your display resolution
   
   

If the problem still appears, remove all external monitors and check if the problem persists.