Dual Wan when USB = Primary Secondary stays "Unplugged"

[Rudi Pittman]

I have both a wan connection and my T-mobile V10 phone with android tethering enabled. I've tried Wan Primary and USB secondary which appears to work fine but when trying USB Primary and Wan Secondary it always shows the secondary WAN as cable unplugged. I'm on the latest stable build that I know of(380.66_6).

I'm not sure what to include so let me know what files I should upload and I'll get them up here.

RT-AC68U (TM-1900 with Merlin installed)