Is mystical experience a hallucination?

Mystics who have claimed that they have a direct vision of God
have always described that God as spaceless and timeless. But mystical experiences have been discarded by secular-minded people as merely a hallucination.

Here is a Medical Definition of Hallucination: A profound distortion in a person's perception of reality, typically accompanied by a powerful sense of reality. A hallucination may be a sensory experience in which a person can see, hear, smell, taste, or feel something that is not there.

That means a person having a hallucinatory experience cannot have any knowledge about reality.

Physicists in this 21st century are saying that spacetime is emergent. For example, theoretical physicist Sean Carroll who once wrote an article showing that God is not a good theory has recently published a book whose title is this: Something deeply hidden: quantum worlds and the emergence of spacetime.

Spacetime is emergent means there is something more fundamental than spacetime from which spacetime has emerged. This something more fundamental than spacetime cannot be within any spacetime. That is because there cannot be any spacetime before its emergence. As it cannot be within any spacetime, so it will be spaceless and timeless. However, physicists describe this as non-spatiotemporal, a new scientific term that replaces old spaceless and timeless. Space and time were two different entities in the pre-relativistic era. In the post-relativistic one, they have become one single entity: spacetime. So physicists can no longer use the old term spaceless and timeless; instead, they use the new term non-spatiotemporal.

That means physicists are now saying that there is something spaceless and timeless from which our known spacetime has emerged.

Now, my question is: If mystics had seen only a hallucination, then how did they come to know that there was something spaceless and timeless long before physicists had come to know that? That is because, as per definition, a hallucination cannot give any knowledge about reality.