Hello,
Turn off the FaderPort 8.
Open the Audio MIDI Setup application. Finder > Applications > Utilities > Audio MIDI Setup.
Open the MIDI Studio window. Window > Show MIDI Studio.
Remove all FaderPort devices from the MIDI Studio.
Power on the FaderPort 8 and select the proper mode for your DAW, which if you are in Studio One you will want to select Studio One mode, and then exit the setup menu of the FaderPort 8.
You can then check for firmware updates in Universal Control.
*Ensure that you are using Studio One 3 version 3.3.2 or higher to utilize the FaderPort 8 in Studio One mode.
Remove any previous instances of the FaderPort 8 from the External Devices and create a new instance of the FaderPort 8 with the MIDI Send and Receive set to FP8.
If you have further issues please submit a technical support request for further assistance.