I think there are some sleights of hand in quantum physics theory that obfuscate determinism, but there is no escaping causality in the quantum realm and more than there is the possibility of defying conservation laws or thermodynamics.
It's just that QM are causal but not determinist. Biology too, BTW. I'm fine with the concept of causality, it's useful, but determinism is an add-on that assumes a humongous lot -- e.g. that this present conversation was bound to happen of all eternity in exactly the way it's happening now, typos included -- and that serves no purpose that I can see. In fact it's disempowering.
To use Leadfoot's apt terminology, the fact that "**** happens" doesn't imply that it was bound to happen of all eternity.
So what exactly do you mean by 'deterministic' then?
Every cause has antecedent causes. Causation is not singular, though, but rather multiple causes interact to produce effects under conditions that were also caused by multiple antecedent causes.
Reality is complex and interactional, but does that make it less deterministic? I think you could assume that if multiple causes interact, there is some way things could happen in different ways, but ultimately they don't because they can't.
Put in human terms, let's say you are choosing between pizza and a sandwich for lunch; your mind is primed to (for example) either choose 1) the sandwich, because you made it and you're not going to waste it to eat pizza; or 2) the pizza, because you aren't going to waste the chance to eat a slice of pizza just because you have a sandwich you made and brought with you. Whatever your mind is primed to choose, that's going to be your choice and you can't avoid choosing what you choose. If you try not to choose, you will still make whatever choice you make, e.g. you won't eat lunch at all because you decided not to choose either the pizza or the sandwich, i.e. because you decided you wanted to resist choosing altogether.
You must go on choosing, whether you think you have free will or not. There's no other choice besides choosing.
You could just say that agency is a way of interpreting actions. That's why I say you can apply the interpretive frame of agency to a human choosing what to eat, a ball choosing where to bounce and roll, and/or God creating the universe, separating the water and the firmament, telling the living things to be fruitful and multiply, etc. etc.