Contents of a certain folder are not getting indexed

[Dariush]

I am running the latest version of Everything (but this was present in the previous one, though I don't remember which specific one it was). This will be a bit abstract, since I can't think which details would be relevant.

There is a folder on my computer with a bunch of files which are not getting indexed. The folder itself is indexed, but the files inside are not. There is nothing relevant in my exclusions.
If I rename or move the folder, files don't appear.
If I rename or move (and optionally then move back) any file, this specific file gets indexed.
If I edit a file, it doesn't appear.
Adding and removing the folder from exclude list indexed its contents.

As far as I can tell, this was the only folder with this problem (and I've never had anything like it in the years I've been using Everything). What might be causing this?

[therube]

What folder?
Is it a folder of hard links?

Does a Force Rebuild of your index correct things?