Indeed, I have moved it accordingly

Sounds like Tridion Docs to me..?

Hi, Roy. While it's true that many map updates can (and should) be made using Pub Manager, our writers frequently need oXygen to edit the metadata in their maps. Also, as an admin, I frequently open maps in oXygen to perform troubleshooting. So, my team would very much appreciate being able to use "Check Out" rather than "Check out With."

Yes! Four years in, and this still trips me up. Why should I have to remember that "Check Out" opens a topic in the editor, but I need "Check Out With" to open a map? 

With us, it is very rare that a folder needs to be modified in an editor like Xmetal. Most of the functionality is available in the publication manager. However, if we need to open a ditamap we can use the "Check out with..." option that can be accessed via the context menu. Maybe this is also a solution for you?