Audio out of Phase and disappears on iPhone

The below problem was solved by realizing that the left and right channels of the audio commentary were out of phase and would cancel each other if listened to in mono. By deleting one channel, the sound came back.

HOWEVER, I am wondering if anyone else has had the same problem with connecting a duplicate source into the left and right channels of the new ATEM Television Studio HD. I am outputting from the left and right channels of a tiny mixing board with separate cables and have never come across this problem with any of my other equipment.
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I produce videos for MMA productions, and on my latest videos, the commentary does not play if I play it on an iPhone. You can't hear it. You can hear kind of a static sound, but not the actual commentary. Test it yourself. Try playing this link through an iPhone (I have a 5SE) and then play it through the computer.

The commentary starts at 7 seconds, and then gets really loud at 17 seconds. Play it on an iPhone, then use headphones or ANY other speaker. All other fights on this same channel that were uploaded this month have the same issue.

Please don't comment on the ethics of MMA. The guy that got hit is OK. He just took a short nap. I am only interested in fixing the sound issue for my fans who watch on their phones.

The problem started the night we broadcast the event. Anyone who watched the Facebook feed on the iphone could not hear the commentary. I've tried changing to MONO. I've tried switching from 44.1k to 48k. I've boosted the volume. I've cut out every single other audio and isolated the commentary track (and you can hear crowd noise, but not the commentator). The only thing I haven't done is changed the EQ.

Getting an out of phase signal is often caused by a mis-wired cable. If you use a balanced XLR cable, there are three connections. So the same colored cable should connect to the same pin at both ends. For instance: pin 1 is shield, pin 2 is red and pin 3 is white. As long as it's hooked up this way, the cable is not the problem. However, if say, red is pin 2 on one end, but is pin 3 on the other, you've reversed the phase. Phase reversal can also be introduced by a mixer if it has a phase reversal switch.

I don't have a TVS HD, but do use the audio inputs of the other models of ATEM, and sometimes with dual mono signals. never an issue. I'd check your input cable wiring as suggested. or try using an XLR Y-cord connected to just one mono output from your mixer into the ATEM.