iRig Pro Duo I/O output to Mac or iPhone is mono

[SachaG789]

I'm sure this has been asked before, but I couldn't find an answer by googling or searching here.

Basically, I just purchased an iRig Pro Duo I/O and when connecting it to either my Mac or my iPhone (using the included iRig to USB and iRig to Lightning cables), I'm only receiving a mono signal even though I can hear the sound in stereo in my headphones plugged to the monitoring port.

How can I get stereo sound? Do I need to plug in my audio source to both iRig Pro Duo inputs at the same time? Or is it a matter of not using the right software to decode the signal properly? Or am I just supposed to receive a mono signal and convert it to stereo afterwards?

[SachaG789]

I think this is the same question asked here: viewtopic.php?f=9&t=25738

So am I correct that this is how it's supposed to work, and you're supposed to convert the signal back to stereo on your own? Is this a common limitation for this kind of audio interface or are there other products that would do a better job of providing stereo sound straight out the box?