Courts have ruled that you can't assign copyrights to a machine, because only humans qualify for human rights. ** There is not currently a legal consensus on whether or not the humans using AI tools are creating derivative works when they use AI models to create things.

** this case is similar to an old case where a photographer claimed a monkey owned a copyright to a photo, because they said a monkey took the photo completely on their own. The court said "okay well, it's public domain then because only humans can have copyrights"

Imagine you put a harry potter book in a copy machine. It is correct that the copy machine would not have a copyright to the output. But you would still be violating copyright by distributing the output.