Exporting a file in MP3 skipped sections and repeated sections in the recording

I have a podcast that I record remote guests through zencastr. I edited a recording of an interview after downloading from zencastr through Audacity. I had to combine two different recordings of the same person, but I finally got it finished. I exported the file as an MP3. Unbeknownst to me, when I did that, something weird happened to the file. First, it skipped about five to 7 minutes in the middle and then it repeated a section at the end.

When I clicked on export, I received this message/content box:
“Your tracks will be mixed down and exported as one stereo file.” I did click OK because I thought I had to.

I don’t remember if I ever received that message before or not.

I have two tracks. One of the recording with the guest; the other of the music at the beginning and the end on the same track. Perhaps, I should have put the music that ends the podcast on a separate tract?

I have never had this problem before, and I don’t remember if I ever received that box about combining the tracks. The recording was only about 47 minutes, so not real long. I only noticed any of this AFTER I published the podcast.

Thanks so much,

You can get this message when you are using the Advanced Mixing Options: Import / Export Preferences - Audacity Manual

Yes. I realize this now. After some research, I discovered that this glitch happened when I uploaded my MP3 file of this recording to zencastr. That’s when it happened. I listened to my exported files on my computer, and they were correct, but something happened in the upload.