Just to make sure that things are, as I think they are, when you play your Timeline you not only hear the Audio from both Tracks perfectly, but also the Levels Meters reflect good Levels. Is that correct? For a test of the Levels, I'd watch in the Audio Mixer. Also, keep an eye on the sliders for that Voice Track. It should not move.
Now, as you can hear both Tracks fine, there should not be an issue with Muting, or with Tracks being Enabled. If the Levels are good to your ears, and with the Meters, good to your eye, the only thing that I can think of would be Track Mapping. Has that been used? If so, where are the Tracks being Mapped to?
As another test, Duplicate the Voice Clip(s), and Copy them to another mono Track. I would probably use Balance to bias one a bit left, and one a bit right. Listen, and then do a test Export to check.
Just grasping at straws here, as I have no clear idea what could cause the problm that you describe.
BTW - what is on Audio Track 1 - just curious.
New track - works in pp ... not when exported
Biasing the sound - works in pp ... no audio from either track when exported
One thing to note ... the audio I'm losing is coming in as a sequence from another project. Not sure if that means anything or not. In the earlier drafts it was working fine ... then it stopped.
Here I come, with more "straws" in my hand...
As a test, let's go back to that eariler Sequence, and try an Export of just the Audio, to a PCM/WAV @ 48KHz, 16-bit. Then, Import that WAV into your new Project and use it in your Sequence instead. Test.
I still cannot come up with a good reason why you are getting the desired Audio w/ proper Levels in PrPro, but then it's missing in the Export. I think that we've ruled out about everything, such as Enable, Mute, Track Keyframes on Volume, etc., but there could be just one little setting, that is being overlooked. So many things that affect Audio, but those are usually heard in PrPro, prior to Export.