The FaderPort 2018 is able to be used with a USB hub. However, not all USB hubs are created equal.
Using a non-powered USB hub may actually cause connectivity issues. A non-powered hub relies on the USB bus power from the USB port from the computer the hub is connected to. If multiple USB devices are being used and connected via a non-powered USB hub, the single USB port providing power and bandwidth may not be able to provide enough power for all connected devices.
Using a powered USB hub will help to remedy this issue. A powered USB hub will have an independent power supply in order to provide power to all connected devices. This helps to ensure that any USB devices that are connected will receive adequate power for proper functionality. Even so, there may still be problems. MIDI devices such as keyboard controllers, drum pads, and control surfaces are sending and receiving information to and from the connected computer in order to communicate and work effectively inside of the DAW. External hard drives are also a culprit of this as they require a high bandwidth in order to send and receive data from the drive itself to the DAW if the drive is being used with the DAW. Having multiple devices connected essentially over a single USB connection can potentially cause problems with devices communicating effectively and correctly.
The solution to both problems above is a powered, Multi-TT USB hub. A "Single-TT" hub (also called "per hub") device has one TT in the controller, and a "Multi-TT" hub (also called "per port") device has one TT for each port in the controller. A "Multi-TT" hub enables 12 Mbps bandwidth for each downstream port theoretically. Essentially having a powered, Multi-TT USB hub is helping to ensure that each connected device is receiving the needed power and bandwidth to function and communicate properly.
Do I need to use a powered, Multi-TT USB hub if I'm on a Mac?
While Mac computers are generally less prone to having USB power/bandwidth related issues by comparison to PC's this does not mean that a powered, Multi-TT hub is not necessary. Even Mac computers may require the use of a Multi-TT hub if multiple USB devices are being used.
If you are experiencing issues such as failed firmware updates or automation not being read by the fader this may be an indication of a communication issue where a Multi-TT hub may be the solution.