Unless you're supposing something mystical or supernatural about how brains work, then yes, it is "just" math, there is nothing else it could be. All of the evidence we have shows it's an electrochemical network of neurons processing information. There's no evidence that suggests anything different, or even the need for anything different. There's no missing piece or deep mystery to it.
It's on those who want alternative explanations to demonstrate even the slightest need for them exists - there is no scientific evidence that exists which suggests the operation of brains as computers, as information processors, as substrate independent equivalents to Turing machines, are insufficient to any of the cognitive phenomena known across the entire domain of human knowledge.
We are brains in bone vats, connected to a wonderful and sophisticated sensorimotor platform, and our brains create the reality we experience by processing sensor data and constructing a simulation which we perceive as subjective experience.
The explanation we have is sufficient to the phenomenon. There's no need or benefit for searching for unnecessarily complicated alternative interpretations.
If you aren't satisfied with the explanation, it doesn't really matter - to quote one of Neil DeGrasse Tyson's best turns of phrase: "the universe is under no obligation to make sense to you"
If you can find evidence, any evidence whatsoever, and that evidence withstands scientific scrutiny, and it demands more than the explanation we currently have, then by all means, chase it down and find out more about how cognition works and expand our understanding of the universe. It simply doesn't look like we need anything more, in principle, to fully explain the nature of biological intelligence, and consciousness, and how brains work.
Mind as interdimensional radios, mystical souls and spirits, quantum tubules, none of that stuff has any basis in a ruthlessly rational and scientific review of the science of cognition.
That doesn't preclude souls and supernatural appearing phenomena or all manner of "other" things happening. There's simply no need to tie it in with cognition - neurotransmitters, biological networks, electrical activity, that's all you need.