I’d say it’s not 100% clear what you’re trying to achieve. Can you please post screenshots of the Syncthing Web GUI from all devices, so that we can see the actual configuration with our own eyes?
This is the default as long as your folders are not set to “Send Only”.
You need to set the folders on them to “Receive Only”. Please keep in mind that there is no distinction between directories and files in this case.
It sounds like you’re trying to solve two issues:
Files aren’t being deleted by Syncthing when you delete them from one of your Devices
You want two of your Devices to not be able to delete files
Please post a screenshot of the GUI from all three devices.
Please take a look at Folder Types — Syncthing documentation – could your use case be solved by configuring the Folder as Send Only on the one system, and Receive only on the other two?
That doesn’t sound like synchronization, which is the goal Syncthing was written for. It keeps a certain folder identical between devices, but what you want to do is more or less just a file transfer in one direction.
There are some instruments in Syncthing to achieve “one-way synchronization”, namely receive-only and send-only folders. You might also want to experiment with the ignoreDeletes advanced setting, but it’s use is discouraged because it always results in out-of-sync conditions.
The easiest way would be to sync all three devices with send-receive folder type. You can then manage the files on your “host” WS02, including deleting them, which will propagate to WS03 and WS04. But preventing deletion on WS03 or WS04 to propagate to the others is not something Syncthing can do sensibly. Note that in this setup, WS03 could delete a file from WS04 as well, even if WS02 were configured to ignore the deletion.