The following is mentioned in the guidelines for a problem setter
You will have to reply / moderate / approve the comments on your problems when they are used in a contest at the soonest. For short contests, you have to be online during the whole duration of the contest. For Long contest, you have to login every day to approve / reply comments. The tester/ editorialist may help you in this, but it is primary responsible of the problem setter to address the comments.
Although some problem setters might not follow this guideline. A reply within 3/4 hours for a long contest is unreasonable, the setter also has his own responsibilities like work/school/sleep.
To add more commentary onto the reply of @vruttant1403:
Yes, the answers to the question may not help with finding a solution; their sole purpose is to clarify the problem statement. However a reply like
You’re question asks about an approach to the problem, but I may only clarify the problem statement. If something in the statement is unclear to you, rephrase your question to ask about that ambiguity
would be totally a reasonable answer in such a case.
Furthermore, replies to comments are not publicly visible by default. This means you might get a private reply. Take as example https://www.codechef.com/OCT20B/problems/ADDSQURE, for which I was editorialist. When logged out the comment section I can only see a single comment from me. When logged in I can also see I have replied to many users privately. Those replies would only be visible if both the original question and the reply are set to published.