The last level is challenging. There are two monitors on the level, one that shows the 1st and 3rd number of the code, and another one that shows the 2nd and 4th number of the code. The tricky part is combining those two hints to get the full code in time.
Also, just a friendly reminder that the code changes to a random new combination every time you respawn.
If you think the error might be because of a bug, please do let us know, but to our knowledge, there shouldn't be any issues inputting the code.
Thanks for checking out the game!