Hi, I observe the same problem as you. After long journey of try and error, I think it is the problem of file version. I found that any files exist on device B while adding the sync folder F for 'read only' wont be indexed and wont be overwritten by syncing. A Q&A question: The same goes for modified files, as it suppose the files versions are newer when files are modifies on B, but it won't sync back to master device A, and it don't make sense to overwritten your newer version with the older version on A, so the file stop syncing unless it is removed on device B. What I want is something that the master device has the executive power to overwrite any files on other devices of the same name, regardless of their version. So that the folders in synced devices always follow the files of the master folder. Are you expecting the same thing? I hope it can help.