Can not get edits to stick to clips

Hi everyone, new here. I am trying to edit a video with 3 video tracks. Track 1 is my footage, with no green screen. Track 2 is a image to be used on track 3, and track 3 is my friends footage on a green screen. My problem is, the 3rd track has bad lighting, so I have to key out a lot of random glitches with the green screen footage. There are a few points where I need to add all those colors back in, and make a curve window to get keyed out instead. But when I make any edits to a clip, the keyed out colors and windows are applied to all clips on that track. This has never happened to me before, so I am a little confused what is going on. Any help would be great.