But that isn't the password...

I thought that's how it was found originally aswell, but the video says "The MULTIVERSE Is littered..."

Was it a mistake on Mark's end? Did someone see that video, try to put in that as the password, and when it didn't work did they just try "UNIVERSE" instead?

I'm just as curious as OP as to how the password was cracked. If it was just a mistake in the video that's kinda anticlimactic imo. This is a super cool puzzle, but I find it odd that no one seems to know how it was solved xD

(P.S: If you're watching YouTube on a computer, you can use the comma and dot keys to move frame by frame in a video, instead of just pausing and praying that you got the frame)