I did some searching prior to writing this and I see similar posts, but none that match my specifics. I am running the server on a raspberry pi with a Flashforge Dreamer 3d printer hooked up to it. My client is a Mac running 10.14.2. I can see the device in the client list, and I can see that it is in use by me, but when I try to launch either Simplify3d, or the Flashforge FlashPrint software, the device does not show up. I saw windows client instructions that had the user use a -3 flag and that seems to have worked.
What I see is that there are no ports available in the /dev/ listing on the client. Another thread on the support forums had a user run ioreg and system_profiler commands. I did that on mine and I DO see the Flashforge Dreamer 3D printer device show up in the output of those commands.
| +-o FlashForge Dreamer 3D Printer@1100000