I have three monitors on my computer. I have geany version 1.33 installed. When I click any of the tabs, File, Edit, etc. the drop-down menu occurs just below the menu item. I just installed geany version 1.38 tonight. When I click on a menu item it opens on a different monitor. In my case to the right of the geany editing window.
If you should need more info, just ask.
Thank you,
Mark