This is one of those weird questions in Quantum Mechanics where there is no way to visualize the answer. Our brains, understandably, have evolved to handle falling rocks, jumping tigers, and other macroscopic objects. We have numerous hardwired responses to these things which follow classical, Newtonian Physics.
On the atomic and subatomic scales where objects behave according to the laws of Quantum Mechanics things are different. An electron can behave like a wave in this experiment, but a particle in another experiments. According the classical physics (and our macroscopic-loving brain's "common sense) nothing can be *both* a particle and a wave.
So what is an electron? A wavicle? A particle?
Nope. An electron is a, well, an electron. Sometime it will behave *exactly* like a wave, other times it will behave *exactly* like a particle. Never will it behave like some intermediate or mixed state.
The problem - to the extent there is a problem - is that we cannot visualize this. There is no way to form a picture in our heads the same way we can form a picture of a ball flying though the air. Our brains are meant to operate on macroscopic phenomena, and subatomic phenomena just behave differently.
Presumably some other alien species could have some sort of mind, or mind-like thing, for which the whole wave-particle duality thing just makes perfect sense! But presumably this aliens would be confused by what are to us the simple motions of a ball flying through the air.
So, in the Copenhagen Interpretation of Quantum Mechanics, there is no sense in which the "other forms" of an object change after a wavefunction is collapsed. That this seems to be a problem is more a function of our brains and how they have evolved.
(As an aside, it should be said that it is possible to understand the mathematics underlying Quantum Mechanics. And to be able to use this math to make extremely accurate predictions of how electrons, atoms, etc. will behave. These predictions can be tested experimentally and Quantum Mechanics holds up extremely well. o while QM is very weird, there is an enormous amount of evidence that it is correct.)