I have the same problem with my Geek Out v2 + that I had purchased in preorder a year and a half ago and is arrived the day before yesterday, the single ended output is working correctly but with the balanced output works only one channel (the left) and from right channel does not receive signal .
I performed the test with 2 balanced cables terminated with TRRS 3.5 mm connector that work well with the balanced output of my HiFiMan 901 Dap .
I have today opened 2 tickets and i hope in a reply.
So I have to think that lh labs do not test their products before sending them, while being aware of a problem in the specific model? Consider that I am Italian and I do not know if I want to address the relevant expense of shipment and wait another year before the repair.
In my tickets I requested the specifications of the plug 3.5 TRRS that they adopt but at this point I do not know if that's the problem ...
However if it were a defective device I will try to give wide publicity in the web of the whole affair.
Thanks for the reply.