Quality Assurance Projects - Sudoku Solver

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Describe your issue in detail here.
Hello, I am trying to complete this Sudoku Solver, and I completed all but the last test, where the second functional unit test (2_functional-tests.js). I am not sure why it is not letting me pass. I had made 14 functional tests, I had run npm test, all of the 14 tests passed in my program, and NODE_ENV = test is included. If there is anyone who could explain or solve this problem, I appreciate it. Thank you for your time in looking into my problem. I hope this post may help others who have the same problem.

Challenge: Quality Assurance Projects - Sudoku Solver

Link to the challenge:

This is my link to my code
Sudoku Solver FCC - Replit