I've become a little frustrated with Code Review. They said my code does not output a valid Sudoku when it in fact does. Is it that people are confused of my code and don't realize that it's in fact working?
Questions can be on-topic and still attract downvotes.
The general rule for downvotes is to cast them when:
This question does not show any research effort; it is unclear or not useful
That's the exact hovertext when you keep your mouse over the downvote arrow.
In theory (not in practice), downvotes have nothing to do with a question being off-topic or not. Close votes are not downvotes and vice versa. Questions can have many downvotes while still being on-topic and at times high-scoring questions get closed because they're not within the scope of the site.
Off-topic questions get closed, bad questions get downvotes. So, apparently, people think it's a bad enough question to warrant a downvote. All downvotes cast (the current score is (+4/-4) before the re-opening are probably (partially) related to the question being off-topic. The rest are, probably (we don't know for sure unless the downvoters answer your question themselves) related to the quality.
As you've indicated yourself, your writing style is a bit confusing. There are abbreviations you don't explain (SAT, is that a standardized acceptance test?) and your description is unclear:
Input should be like a tuple.
That's a list, tuples have braces
( ) instead of brackets
Your last paragraph reads like you're not sure the code works.
How would I know that my code indeed generate n! of all n^2 x n^2, and of course what are my mistakes in the code?
Did you test it? Do you have any code validation set-up currently?
Luckily we got a FAQ on improving questions: How to get the best value out of Code Review - Asking Questions
If you know your writing style is confusing, consider clarifying the question so it's less confusing. But downvotes and close votes are separated.
https://repl.it/repls/WrathfulYummyTransversal is currently "Offline for maintenance" (which is why it's a good idea for why to include all the relevant code in the question itself).
Right now I can't tell if all the code is there or not, but assuming that it is I just read it briefly and noticed "There's no way this can generate a Sudoku puzzle" (Yes, I read your question as "Sudoku puzzle" - perhaps incorrectly). And even if it's just generating a grid, I read your code again and felt that there's no way that this can generate a random or even more than a single grid. So I felt that the question was unclear and misleading and the code uninteresting. Therefore, I personally down-voted.
I would strongly recommend to read Simon's guide for posting a good question for the future.