In recent versions of Vivaldi, the menu has started appearing on the right side of the window.

Vivaldi in Xubuntu  with menu on right side of screen

I am a stickler for usability, and so I want a menu showing. I also follow the original human interface design guidelines of trying to have window controls on the upper-left corner of windows/screens.

Any insights into how to fix this display bug in order to get the menu back on the left side of the window?

This bug is showing up on all my computers. Here are the basics:

System:
Kernel: 5.17.5-76051705-generic x86_64 bits: 64 
Desktop: Xfce 4.14.2 Distro: Ubuntu 20.04.4 LTS (Focal Fossa)