Don’t think the OT can do MIDI over USB. You may need to use the DIN sockets. USB is mainly for getting files in and out of the OT. Overbridge is the much-awaited way for DAWs to talk to Elektron, but only for recent boxes like A4 and Analog Rytm. Older boxes like the OT, MM etc aren’t part of this sadly.

If I’ve got the above wrong, no doubt I’ll be standing corrected;-)