Hello.
Have you tried “hard links” rather than “symbolic links”?
Symbolic links have the extension .symlink, visible in the file properties.
It’s not actually a .md and Obsidain doesn’t recognize it.
However, hard links keep the file extension.
In Osidian, the changes are not synchronous (snapshots): if you modify the contents of the file in a side application, you must save it to see the modifications of the file update in the open window of the Obsidian. Or update the file yourself. (Tested on Win10).