Camel ftp consumer ignores idempotent file repository on start

I have created a route that consumes from ftp:

private RouteDefinition ftpRouteOcs() {
IdempotentRepository<String> fileRep =
FileIdempotentRepository.fileIdempotentRepository(new
File("./downLoadedOcs"), A_MILLION, TEN_MB);
// from endpoint
FtpEndpoint<?> ftpEndpoint =
getContext().getEndpoint(config.ftpUrlOcs(), FtpEndpoint.class);
ftpEndpoint.setIdempotentKey("${file:name}");
ftpEndpoint.setIdempotentRepository(fileRep);
ftpEndpoint.getConfiguration().setBinary(true);
//important!
ftpEndpoint.getConfiguration().setStepwise(false);
// no write or move operations - read only, set idempotent to true
ftpEndpoint.setNoop(true);
// only include files that match pattern
ftpEndpoint.setInclude(OCS_FILE_FILTER_PATTERN);
// fetch 1000 files in one poll...
ftpEndpoint.setMaxMessagesPerPoll(FTP_MAX_FILES_PER_POLL);
// but sort ALL files before...
ftpEndpoint.setEagerMaxMessagesPerPoll(false);
// ...by file name
ftpEndpoint.setSortBy("file:name");
// to endpoint
FileEndpoint fileEndpoint = getContext().getEndpoint("file:" +
config.ftpTargetOcs(), FileEndpoint.class);
// mark finished downloads
fileEndpoint.setDoneFileName("${file:name}.done");
// ignore if exist
fileEndpoint.setFileExist(GenericFileExist.Ignore);
return
from(ftpEndpoint).to(fileEndpoint).routeId(RouteIds.ftpOcs.name());

As you see i am using fileIdempotentRepository. The file is created fine and
each file downloaded is added to the file - i get all related debug outputs.
The problem is after a restart all files are downloaded again - the
repository is ignored. The file is still there and on each run the file is
updated - with the same data (create date keeps the same, change date is
updated).
so what is be wrong with my setup?

Thanks in advance