It is not “just” quantum physics that shows the deterministic universe is impossible.

Relativity theory shows, there is no “universal clock”, this is distinct from Newtonian physics which assumes a single universal clock.

You may not want to accept that the universe is not deterministic, and there are big gaps in our understanding of reality, but this isn’t one of them. On a fundamental level, the universe is probabilistic.

You are in good company however, Einstein famously said “god doesn’t play dice with the universe”, when he initially discovered this fact. He came to accept its reality, at the evidence is overwhelming.