I may have asked this before but lost answer, my Korg N364 is hooked up with a single USB midi cable to computer/sequenser. The N364 has a module attached at thru, so the sequenser echo back what is played to sequenser, and then to module. But this also means that what is sent out from synth is echoed back to synth "double notes".
I think someone said "keyboard to synth engine" can be turned off on most keyboards. But i do not remember "what terms to search for", the name of functionality.