Multiple builds of the same design has different timing closure results

Neither of those would cause it to change.

Why do you want to recreate it? The main cases I've heard are:

- If you have a golden build that is sent out to the field, you want to be able to regenerate it. I completely get this, but recommend saving everything about the project, including /db and /incremental_db, so you can just open it up without recompiling. Memory is generally pretty cheap, and there is no risk of "can I recreate this".

- Different people compiling and getting the same results. I'm not sure on this one, as generally I would prefer to see what the seed variation is. If I really need to look at the other person's results, I can just get their .sof and download it, or open their reports or whatever.

- Just the feel good of repeatability. I completely get this, and again, there is no random number generator in Quartus so it should get the same results(and I have seen it do it often), but I usually find there isn't a huge reason why it's necessary. (The biggest one is when someone has a bug that only shows up on certain builds, and Intel is trying to recreate it on their end without having the whole /db sent over)

That's not actually answering your problem, but maybe I can help another way. (FYI, different operating systems, like Linux vs. Windows, will give different results. You're compiling on the same machine so that's not it, but I've seen that catch people)