Static In Portion Of MP3 Exported File

Hello! I have searched relentlessly for solutions on this message board and on others before posting and have yet to find a solution to my issue. 

I have an audition session (podcast episode) and the entire recording sounds wonderful in my multitrack and waveform versions. Then, when I export the file to MP3 format (ive tried both exporting with media encoder and multitrack mixdown), on playback, I hear a static noise that buzzes randomly at the 1 hour mark, and continues to the end. The first hour of the episode is pristine. 

I checked the entire audio file and this does not happen in editing, so I know it has something to do with the export. There are NO issues on the file in audition. There is no static or any issues in the waveform view. I have the correct exporting settings, file and stereo/bit settings.

I do not have any edits on the file except for background noise reduction, and some upper level spectral selections. Ive checked and rechecked the raw audio file and there are no issues. I have re-exported, re-edited, with no success. Ive had a friend listen on another player and she hears the noise as well. 

Keep in mind i have edited 38 podcast episodes thus far and have the same settings every time, with no issue up until now. 

Please help as I am at my wits end. 

Thanks