ATEM Studio Audio Encoding Problems

We have recently run into an interesting problem with our audio encoding. We first experience this with a new ATEM Studio HD Professional switcher. We reverted back to our old ATEM Studio thinking that was the issue but it has still persisted.

The problem is that we get very low audio signal coupled with digital noise on mono devices (i.e. iPhone 6s and below). This is also a problem because apparently Facebook Live also only sends out a mono signal, which makes our Facebook Live feed useless. On the iPhone 6s (and below) if you listen through the external speaker you can't here anything but low level garble. If you then put your headphones in, it's crystal clear. Has anyone ever experienced this?

Also, we use a Digico S21 Console to send the mix through a camera to ATEM. With the HD Professional, we used the XLR inputs and got the same effect. It could definitely be the sound console but we made no changes to it over the last few months.

Thanks.

{UPDATE}
We figured it out. Somehow on our audio console we had changed the polarity of the left output. So...if you ever run into this problem that is a good place to start. Note, it will only show up in Mono situations.