I was going to cut a few seconds off a video clip & when I played it, it slowed it down. At first I thought it was the normal thing After Effects does but when I exported it, it exported as that slowed down version as well being way more pixelated than it should be. I even put it into Premiere & it's doing the same thing. I'm not sure why it's doing this.
Sorry, but this is not in any way useful. You have not provided any info about your system, exact specs for the file like what CoDec, frame rate, dimensions and so on. chances are it simply needed a change of footage interpretation or something to be used and work correctly in AE.