Personally, I don’t know the personal reason why Bartleby chose to not do work but as said he exercised passive resistance and declared his individual power. With the story he is basically saying no to do work that he was hired to do. He was a great worker until he decides to refuse to work. He uses the notable “I prefer not to work” which presents a gentle and polite response.
However, it could be said that since Bartleby prefers to not adapt to change and would prefer a “stationary” life where things stayed the same. This could be attributed to his refusal to do work since he prefers to make copies and similar things but would prefer to not compare which means that he would have to argue and work with someone.
If I was working with Bartleby, I would simply ask him why he wouldn’t do work. If his answers are unsatisfactory, I would explain to him why it is important for him to do the work and it is the reason why he was hired. If nothing changes, then I would have no choice but to let him go but it does not mean that we cannot be friends and talk on a personal level.