Not saying this is what you're doing, but I find requiring someone to solve a problem immediately after sharing it can (ironically) stifle finding a solution. The act of identifying and the act of solving rarely happen all in one motion, and often the first step to solving a problem is to establish its validity among peers so meaningful solutions can arise.

Yes, but: The top level comment specifically said they were working to solve the problem. I think in that case it's worth asking about their approach.

Tangent to this: I think it's often useful to allow suggesting "bad" solutions to vague problems because good solutions often hang out close to the bad one's and shines interesting light on the problem. Or bad solutions often immediately provokes better ideas. If you immediately see that a proposed solution is bad there's a good chance you know what specifically is bad about it and can propose an amendment.

Suggesting a bad solution is sometimes half the way to a good one.

Exploring the problem space is necessary to determine what a bad solution versus a good solution even is.