So I've been attempting to upload converted MP3 songs into itunes but they are always twice as long as what the original video actually is. I even checked the file’s Properties and the length is what is listed. Not sure what’s going on. I’ve attached a log below.
Your logs say the duration of the m3 file is 00:06:48, which is the same duration as the source video?
2020-07-16 12:24:24,561  INFO c3 [(null)] - LibraryManager: 6: Format type is Music
2020-07-16 12:24:24,561  INFO c3 [(null)] - LibraryManager: 6: Audio is MP3, VBR, 48000 Hz, stereo
2020-07-16 12:24:24,562  INFO c3 [(null)] - LibraryManager: 6: Duration is 00:06:48
The video is 6:48, but as shown in the photo it's twice as long when in iTunes.
Looks like it is a bug in itunes.
Plus many others.
VLC shows the correct duration.
Looks like iTunes doesnt support variable bit rate MP3 files correctly, which is what you have downloaded.
Convert to one of the MP3 conversion presets that has a kbsp and import to itunes, Will increase the size of your files though.