As the saying goes, Brahman is the knower of Brahman. And as I’ve noted, consciousness arises in Brahman. But Brahman is also beyond consciousness.
The key here is the distinction between conscious and consciousness. Conscious in this context is that quality of lively alertness. It knows itself.
However, when that lively alertness flows and becomes aware of its nature as consciousness, it creates the dynamic of self-aware consciousness – knower, process of knowing and known (aka subject, process, and object). Self-aware consciousness (Atman) looks in on itself, creating what might be called a virtual space into which it creates. But in this process, it divides itself from itself and gets lost in it’s own dynamics and forgets it’s nature as Brahman, beyond Atman.
We might call ego identification the local version of cosmic Atman self-absorption.
The process of spiritual awakening reverses this process – first we awaken from the person (ego/ an object of expression) into our nature as the observer or subject. This is Self (Atman) Realization. At some point, we then recognize Self in the world as well – All this is That – which leads to the flowering of Unity. Through a process of experience and become (recognize ourselves as) we come to know the wholeness of Atman. And then Atman can turn and look beyond itself and discover its true nature.
This is how Brahman is conscious but not consciousness.