Weird iCloud sync bug

So a lot of my music in iCloud has either been ported over from cds or downloaded off soundcloud YouTube etc. a lot of those songs have "tails" on the end of them- dead sound at the end of the song. I have gone into my computer and trimmed the audio file to cut out the dead sound and then sync it back into iCloud. sometimes this works flawlessly but other times my phone will continue to have the old file on it but my Mac will show the new file. I've tried converting the file and then uploading it turning off and on iCloud library and it still continues to sync the old files that aren't showing up on my Mac. has anyone had any issues like this and know what to do to fix it or is this just another flaw in apple software that continues to disappoint me daily.