We encountered an issue downoading files from various different ftp servers.
If listing the files to consume fails for whatever reason, the FTP client does not disconnect from the server, even if disconnect=true is specified in the endpoint URL.
This leads to the problem, that upon the next poll, the connection ist still open and the component starts to navigate stepwise to the target folder which will fail, because we are not in the home folder of the FTP user anymore. This leads to an GenericFileOperationFailedException, which will again cause the poll to fail without a disconnect. From now on, polling this endpoint will fail until restarting the containing route.
Adding stepwise=false as an workaround did not work in our case because one of teh external FTP servers will return absolute paths when calling the list command, resulting in an error when trying to download the files.