On the centOS platform, one of my directories was turned into a file

On the centOS platform, one of my directories was turned into a file

This is a directory, originally there were some files, but today I found that it became a file, the name has not changed, and it is also a file when synchronized to Windows, and it cannot be opened.

Syncthing didn’t do that. My guess would be you created an archive of the directory and then removed the zip extension by mistake.