The question What can cause a question to be bumped? says that answers will bump a question.
However, recently I noticed some older questions not being bumped after I answered them.
One example is this question.
I'm wondering if this is a bug, or if there are criteria for when not to bump a question, such as it's age, downvotes (the linked answer for example does note an exception for edits, but not for answers), existing close votes, and so on.
Edit: After asking this question, I upvoted the question I linked, and it got bumped, suggesting that downvotes may restrict bumps. I would still be interested in a general answer though.