Care Ticket Won't Submit; Deepmind 12 Headphones Output Only in Left Ear

Hello,

I have tried multiple times to try and submit a Care Ticket describing a defect I have with my newly purchased Deepmind 12 synthesizer, but each time, the request failed and the website claimed that my Customer Tribe section "This field is required" needed to be completed, despite the fact that I had already put the Musician tribe in that slot. I tried even adding all possible Tribes, and this wouldn't go away and let me submit the ticket, so here we are.

My Deepmind 12 was used, but refurbished by Music Tribe. Whenever I plug in my headphones to the synth, sound only comes out of my left ear. The right ear is completely silent, but the left ear plays in mono. This exact same problem occurred with a previous refurbished Deepmind I recently bought before returning. What is the problem here? I've tried looking everywhere, but no one else seems to have this issue. I thought it might have been a setting I missed, but I couldn't find anything in the menus. The only real thing I can come up with is the image I provided: the adapter I use for the headphone jack so I can utilize traditional 3.5mm headphones instead of the larger size built into the synth. I thought this was the problem, but this same adapter works flawlessly with my Yamaha MOXF8 workstation, so I don't think this is it. Can anybody help me with this?