I'm currently running Studio One 3 on my Mac OS Sierra. I have an M-Audio interface hooked up to my computer/ configured with Studio One. When I plug my instrument in and play, I see a signal coming in on my interface and I've checked the sound under my system preferences not for the DAW but for my computer itself.. and the Mac itself is getting a signal as well. Therefore, this is suggesting that this issue is within Studio One. When I enable monitoring on a channel and play my guitar, both my computer and interface are receiving audio feed, but I get no signal displayed on the channel within Studio One, nor does it even start a recording black after I've armed the track and hit record.