There is no “hard problem”. The language used to set up the hard problem repeats all the known and fatal errors that arise when dealing with experience.
The supposed qualia are experiential, not observable. As used in standard discussion within the field of cognitive science and its philosophy, they are an attempt to take the domain of experience and treat it as a thing – as something to be found in the world. Worse, they partition experience, until all that is left is the poverty of the notion of “redness” or “sweetness”. Experience does not reduce in this fashion. This is the persistent problem: treating of mind, or consciousness, or qualia, as something to be found in the world.
My preferred term, because it helps to get things straight, is experience. Mind, consciousness and qualia are all just confused ways of acknowledging the reality of experience in the first person. And experience is not to be found in the world. Experience is what gives us a world in the first place.
Let us digress, before this becomes bitter, and go back to a fictional Isaac Newton, sitting under an apple tree in rural England, looking at apples, perhaps picking one or two up, feeling them, hefting them, throwing one up in the air and catching it, then biting into one.