Cubase with Yamaha USB - can't get right channel


I’m a newb to Cubase. I bought a Yahama USB mixer that came bundled with Cubase AI6. The mixer USB supports 2 track recording (stereo). I want to do so recording where I pan the vocals on the mixer to left channel, and the instruments (4-piece Rock band) to the right channel, so I can tweak relative levels between vocals and music before mastering tracks for burning to CD as demo songs…

I understand how to configure the AIO device setup, and the VST channel assignments etc… no matter what I do, whether using mono 1 and mono 2, or stereo L and stereo R for my 2 audio track inputs, I only/always get the left channel mixer output on BOTH channels. If I play music from my android plugged into a mixer channel, and pan it to left, the left output meter shows signal on left, and cubase sees that signal, all is well… if I pan the mp3 mixer channel full right, the mixer right side meter shows the signal (and left drops to nothing)… but cubase track that is assigned to mono2 or stereo R for input goes dead… nothing… so, mixer showing signal on right channel, but cubase will only see left channel, no matter how I configure the input… any ideas/suggestions?

In Devices, VST Connections, Inputs, what do you see listed for your Device Ports? What operating system are you on?