I submitted my first ever run and it was immediately declined for "Duplicate Run"? I don't understand why, please help

I haven't had a chance to speak to the one that rejected your run, but I would believe that the reason was actually because of your framerate being uncapped. My assumption is that the mod that rejected your run pasted the wrong message into the rejection box when he rejected your run.

As a quick/brief explanation of why that would be a thing, this website has a number of issues as most people that use it are probably aware of, but for moderators a common issue is that when we click reject, the box that we can type the rejection message into will pop up and usually the website has an error that comes up if you click away from that box. Well, for some reason, for the last many months, that error has been just randomly happening faster than we could even move our mouse from the reject button to the box to type the message. So, many of us type the message into a notepad or something and copy/paste it quickly and hit submit. I would assume, he copied the wrong message or when he tried to hit "copy" it didn't and a message from another run was still in the clipboard when he pasted the rejection message in.

Thank you for the quick response! I was unaware that would cause DQ as the rules it didn't say anything about uncapped, I'll try another run! Again, thank you!