How to compress PSE Window horizontally?

I have a new 26 inch Asus monitor.  I used to be able to modify the displayed PSE Window horizontally and vertically to adjust it's size.  In PSE 2024 I can modify the PSE displayed window vertically but not horizontally.  I usually have mulitple Windows open.  I can modify the Windows of other open software vertically and horizontally but not the PSE window.

What setting do I need to choose to adjust the PSE window horizontally?

Thanks in advance.