MIDI Machine Control is not supported by the SEQ, it's a sub layer of the MIDI norm which is not implemented. Of course the SEQ can receive/send SPP and Realtime messages like start stop continue, midi clock etc..
More than that I think the MPC is not a regular USB MIDI Device and if it's the case it's via an internal USB HUB that the seq does not support.
Then just use regular MIDI DIN connection between the seq and the MPC, this will work.