Studio One will definitely record automation at the same time it records notes. In my example below I recorded automation for filter cutoff at the same time I recorded notes. The filter cutoff automation was captured from me turning a knob on my master keyboard. You should be able to record the fader movements from your MIDI controller as long as they are assigned correctly. Also, you have to make sure that the configuration for your MIDI input device is not filtering controllers. See the second image for the configuration options to check. If your input device is filtering controllers, they will not be recorded.
Note: to see the automation as a separate lane, just click the icon to view automation.