Why does ChatGPT understand the quantum wave function but not most modern Physicists? Scientists today regard the wave idea in Quantum Theory as being a real physical field that, when changed, describes a real physical change of a real field that happens in the real world.

The wave function is a mathematical object that you can get probabilities from. For instance, when you do a double-slit experiment to see which slit a particle went thru, seeing that an electron (for instance) went thru slit A does not mean that the wave function "collapsed" to state A. One experiment means nothing.

You have to do a series of these experiments and see if the empirical distribution of electrons (how many went thru slit A and and how many went thru slit B) is what the wave function said it would be.