I’m just going to use my MPC to stem out the tracks from the S2400 I guess. Which sucks because it’s just an extra step. 
I feel like I’m doing something wrong but I’ve tried everything I can possibly think of. If anybody has any advice then please help. I have the Clock source on the S2400 set to USB B. Settings for Logic are in the pictures below. Have tried switching things around but still cannot get anywhere.
Reset the midi drivers, it’s in another tab in that options folder for logic.
These are my midi settings for controlling my S2400 (& my MPC’s) from Logic. Set your clock source to USB on the S2400 & it should all work - providing your mac & S2400 are connected via USB 
Hi, I just read your post. Your best bet is to get a hardware midi interface that’s USB. I personally use a Motu MTP AV model. You have to make sure the drivers for that model are compatible with your computers O.S. system. The interface is rock solid for sending out MIDI clock and MIDI timecode. The MTP AV gives you 8 simultaneous MIDI outputs and 8 Simultaneous inputs. I just use the outputs to send MIDI Beat Clock to all my hardware. Also, if you can MIDI Sync your MPC then just connect the MIDI Output from that to MIDI input on the S2400 and set the S2400 to receive MIDI Beat Clock Input, (External Sync Mode). The S2400’s Tempo must be set to External MIDI Sync mode instead of USB.
Second Solution: I’m not sure which Audio Interface you’re using but if it has a MIDI Output Jack on the rear then you can also use a MIDI cable to connect your S2400 MIDI Input to that and on the S2400 again choose External MIDI Sync mode Intead of USB. Both of these solutions should work. You also have to set Logic to Send MIDI Beat Clock Output if you have a MIDI output on your Audio Interface you can connect your MPC Input to that Audio Interface MIDI Out and set the MPC to MIDI Slave Mode then connect the MiDI Out cable of the MPC to your MIDI Input of S2400 and set S2400 to External MIDI Sync mode. Just make sure you are sending (MIDI Beat Clock ) Output from Logic. Problem solved, hopefully. Sincerely, Michael