Just curious, ... which ID3 tag versions are written resp. collected within the target MP3 file ...
ID3v1, ID3v2.3, ID3v2.4 ...?
Are there any other tag-types involved ... APE, Lyrics or others?
Which type of bitrate is involved ... CBR or VBR?
Duration?
Do you know which codec or external utility tool and version is used by Audition to encode mp3 files?
See also ... (german)
[F] Falsche Bitrate bei sehr großen MP3s
DD.20151217.1552.CET