Remote Server Syncs that pull files into a Files.com folder can be affected by that folder's Folder Settings.

For example, if a Folder Setting has been configured to Limit uploaded files to certain file extensions then any syncs to this folder will also be affected by that setting and only files that match the allowed file extensions will be successfully synced.

When syncing files to a folder with Folder Settings that alter file contents or filenames (e.g. GPG Encryption, GPG Decryption, or Filename rewriting rules), you should enable the option to delete files from the source.

A sync to a destination folder with a Folder Setting that alters file contents or filenames will not run unless the sync is set to delete from source.

Check the Folder Settings of the destination folder for a sync to determine if a Folder Setting is being applied to the outcome of a sync.