Hi Eva,
You can find logs here - C:\usr\sap\MDM\MDSS02\log
Another thing to check is the write permission on the port by the system.You can take help of Basis for this.
When you manually syndicate file are you syndicating it to the Ready folder or local system?
If you are sending to local system the try syndication to Ready.
Please come back with findings.
Thanks,
Ravi