Quantum mechanics presents the most meaningful challenge to determinism because unlike chaos theory it asserts that reality really is indeterminate. Physicists have been wrestling with this problem since quantum mechanics was formulated. Even Einstein tried to prove quantum indeterminacy was false, but he shrank from the implications of his own solutions.
Spoiler: there’s no strong evidence for most hidden variable theories. There has been a revival of interest in some deterministic re-interpretations of quantum mechanics over the last few years (recommend Lee Smolin, he has a book and some talks on Youtube re this discussion), but right now, the prevailing theory is that reality really is just fundamentally indeterminate. Hey, I hate it, makes my skin crawl, but that’s most likely the way it is based on the science.
EDIT – I’m not a strong advocate for free will in the abstract, but I do think the basic worldview underpinning certain forms of hard determinism has been superseded by a non-deterministic view in physics.