This might be a dumb question but is is staying in link mode?
I have the same balancer and sometimes when I get ready to charge the balancer will kick itself out of link mode. I would make sure it is still in link mode when you actaully start the charge on the charger.
Not sure if this has helped mine or not but I got into a habit of hooking up the + first, then the balancing tap, and last the - wire. I have been doing this the last few weeks and it does not come out of link mode when it it hooked up this way.