Not sending MIDI clock

I’ve tried a known-working stereo aux able, and I’ve tried two TRS MIDI adapters joined by a known-working DIN MIDI cable. bluebox still doesn’t detect MIDI clock. I’ve tested NGEN MIDI DIN out, and while there’s the expected MIDI note and CC info, MIDI Monitor does not report any MIDI clock coming from NGEN or any kind of MIDI sync info. I asked about that at this thread, but I’ve never received a reply.

Everything else about my NGEN works fine, aside from the frequent freezes and restarts that others have reported. But if it also does not send MIDI clock from either of its MIDI outs, then is there a way to rule out that this is a defective unit?