How to make my research productive when my advisors don't give me constructive feedback?
I'm afraid you may not be perceiving the value your advisors offer in the form of these questions. They are prompting you to resolve ambiguities and to put your project on a solid footing. Rather than telling you what to do, they are providing a more abstract kind of help: identifying matters that you should address. This is no less important to your project.

If they think you are making a poor use of time, then share with them the questions you are actually trying to answer. You just need a consensus on what to work on.