Duplicating Project Affects Original Project

I created a video and am now trying to resize the dimensions and trim the video up for different platforms. I select my project in the Event Library and click "Duplicate Project", then I open my new Duplicated Project. My problem is, any edits I make in this new Duplicated Project also get made to the original. I've even tried dumbing it down and copy/pasting the whole original video timeline into a new project, so that is has no ties to the base project, and that still doesn't work. No matter what I do, both projects are edited when I just want one baseline project, and then the more trimmed up versions for social media. I have one compound clip; I read that if you want to continue editing the compound clip in your Duplicated Project, then you must "Duplicate as Snapshot". I don't want to edit my compound clips or anything near them. I just want to edit the duration and dimensions of the video, so I just use Duplicate Project. Is there something I'm doing wrong? TIA <3