In short, Quick Switcher can not work well with the folder / article whose name includes pound key.
This bug can engender several situations:
The pound key is at the front of the folder / article name, etc # reproduction. In this situation, it will turn to create an Untitled one when you try to navigate to the file.
The pound key is in the end of the folder / article name, etc reproduction #. In this situation, it will turn to create a file named without pound key when you try to navigate to the file, etc reproduction.
In both this situations, Quick Switcher can located the file and display them as usual.
This symbol isn’t compatible with actual file names on some operating systems and therefore isn’t recognized by Obsidian, either. If I recall correctly, they show up when you’ve imported a note. You can’t actually create one within Obsidian.
Best bet is to not use them in note titles (ergo file names) at all.
I’m on macOS as well, and yes, our superior operating system can handle things like “#” in filenames.
Sadly this kind of futuristic advanced computing capability is not available to our friends on Windows, and because Obsidian is cross-platform, the app only recognizes a restricted character set to accommodate our anachronistic peers.
I’ve got it. It can be really disappointed if Obsidian make a different rule for different OS that engender some OS depended bugs. And the best way, of course, is to accommodate the incompatible one. I’ve make a feature request to ask for a Sticky Folder function which could help me do the same thing but without using pound key.