The person to whom you wrote responds to your email—but answers only the first of the issues you raised.
That person is guilty of email skimming: replying to only one item, usually the one on the top line.
What happens next? You have to write another email requesting responses to the other matters in your original email—a waste of time and duplication of your effort—or those other issues are delayed. Either option is thoroughly unproductive.
What do you do?
Keeping on topic. Here’s a good suggestion.