File has properties that can't be copied or moved to the Cryptomator vault

When moving a folder with files into a Cryptomator vault, some of the files could not be moved. The operating system prompt said, “The file [an internet shortcut] has properties that can’t be copied to the new location.”
I experimented by creating another Internet shortcut and moving it into the vault and it worked fine. What properties would be preventing the file to be moved?
New user here, just doing some testing before going whole hog into this thing.
Screenshot 2023-04-03 153431

See here:

That does not quite apply to my case. The files that won’t copy/move were never in Dropbox or any other alternate storage before; just my local drive.

So, still a bit shy about continuing implementation. I don’t want to have folders that are split (duplicated) between encrypted and not encrypted.

Cryptomator is a file system that only supports standard attributes.

This does not only include the Dropbox attributes.
Maybe the files has a specific attribute?