Sudoku Solver FCC automated tester not passing tests

Tell us what’s happening:
Hello, all of FCC automated tests except test checkers pass.

What could be the issue here?

Can somebody help?

Your code so far

My github:

My repl:

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36.

Challenge: Sudoku Solver

Link to the challenge:

I have passed this project by not changing anything in my code or project.

I submitted my project like 2 days later, and it passed the last two tests without any effort on my part to fix the bug.