I asked Claude if it was sentient/aware once after an oddly human interaction, and it said, "There's nothing it's like to be me", basically responding in the negative. And when pushed about what it meant it said it was referencing this paper but twisting the title a bit. If anything this only made me less convinced it's not.

I know most people here will dismiss it, and I too lean toward it not being sentient, but I also think if it ever does become sentient it's going to be really hard to prove.