Bhesh! Saying that an object doesn't have definite values for its properties makes the whole concept of properties very fuzzy. Which is quite different from how we normally think of physics
QM doesn't concern itself with how things can be probabilistic. When we say that the electron's spin can be both \(+\frac{1}{2}\) or \(-\frac{1}{2}\), does the electron keep switching spins? Does the electron have both spins and does each measurement fork it off into a different Universe.
QM doesn't say anything about all this. Because all you can actually observe is the result of an experiment. And, QM does a damn fine job of predicting these numbers accurately.