IMO the hard problem is not posed to be solved. I think of it like this. The world in which we are p-zombies is categorically indistinguishable from the one in which we are not, by an objective perspective. It is not a concept that we should use for an objective definition.
It's like saying "a computer that works, but where the CPU is replaced by a piece of stone is physically indistinguishable from the real thing".
We have not yet found a physical distinction. It seems likely that there is one.
https://www.engraved.blog/building-a-virtual-machine-inside/
Read to the ending where it closes the recursive loop.
I'm sure Hofstader would dislike people saying "he was right about this!" "he defined this!", though, since that's not what he was setting out to do at all. GEB really is just an exploration, with some of the results being couched in mathematical language as an artifact of his background, not as an attempt to formalize anything.
You want an explanation for the sensation of the color red? Alright, I'll try, as long as you help me out: what exactly is the sensation of the color red? I need to have a good grasp on what we're talking about here.
Can you describe it? It's okay, take your time.
FIN
And of course the entire point is that qualia are ineffable. That's part of the definition. It's the feature, not a bug. But if you want to deny that you have conscious sensation then go ahead. ;)