The missing mass is tied up in the higher emergence that the galaxies stars combined together form, in the same way that electrons and photons form atoms.
The atom is not a single individual electron, or photon being transferred, or the nucleus, but the emergence of the combination of all of them together.
The Galaxy is the emergence of all of the stars and gasses, planets, their asteroid fields, rings, each possessing their own individual gravity's interacting all together.
The galactic core is creating/building/manufacturing galactic pathways to other galaxies.
They then form local groups, which they themselves then connect together to other local groups to form larger super clusters.
The connections are physical, and require material/mass/matter.
The missing matter is tied up in the higher emergence observation layer.
Also the connections between all of the individual stars within the individual galaxies.
It's building something....fucking massive.