Video develops a "hiccup" / audio glitch at some point in uploading process

[Zen Galileo]

My original video did not have any kind of hiccup or glitch. But I decided to trim out the first 18 seconds of the video. The original version was already uploaded and live and getting some views. I set the original to unlisted. I edited the 18 seconds off the original file creating a new edited version. At this point the edited video file is still on my computer. It does not have any glitches at all. Although later I noticed that it played slightly faster than the original version. I dismissed the idea as impossible because I don't even think my editing software has a function that will speed up a video. I upload the video to youtube, and this is where the hiccup occurs, once it is all uploaded and processed. I went through this whole process several times, deleting previous versions and re-doing them. But every time, it developed this glitch at the last stage. I tried connecting my cable to my internet box in case it was a wi fi thing. Also, the glitch is very rhythmic. It keeps a steady beat so to speak throughout the whole video almost like a scratch on a vinyl record. This is a clue I believe but I don't know to what end.