This is technically not an Ubuntu bug, since the problem originated from code acquired outside of Ubuntu. However rather than mark it as invalid, we might be able to suggest a fix.
Please:
1. Clarify what you mean by "Activity menu". "Activities" is a button, not a menu. And the menu beside that button is the application menu. Which one do you mean?
2. Try: Install 'gnome-tweak-tool' and check that Tweaks > Top Bar > Application Menu = ON
This is technically not an Ubuntu bug, since the problem originated from code acquired outside of Ubuntu. However rather than mark it as invalid, we might be able to suggest a fix.
Please:
1. Clarify what you mean by "Activity menu". "Activities" is a button, not a menu. And the menu beside that button is the application menu. Which one do you mean?
2. Try: Install 'gnome-tweak-tool' and check that Tweaks > Top Bar > Application Menu = ON