The observation of the S-star orbits has established the existence of a supermassive compact object at the galactic centre. However, the G2 gas cloud orbit and absence of observations on event horizon-scale distances have challenged the central black hole model. In addition, the Planck Legacy 2018 (PL18) release has preferred a positively curved early Universe with a confidence level greater than 99%. In this study, the formation of a galaxy from the collapse of a supermassive gas cloud in the early Universe is modelled based on interaction field equations as a 4D relativistic cloud-world that flows and spins through a 4D conformal bulk of a primordial positive curvature considering the preference of the PL18 release. Owing to the curved background, this scenario of galaxy formation reveals that the core of the galaxy undergoes a forced vortex formation with a central event horizon leading to opposite vortices (traversable wormholes) that spatially shrink through evolving in the conformal time. It indicates that the galaxy and its core are formed at the same process where the surrounding gas clouds form the spiral arms due to the frame-dragging induced by the fast-rotating core. Accordingly, the G2 gas cloud that only faced the drag effects could be explained if its orbit is around one of the traversable wormholes but at a distance from the central event horizon. Further, the simulation of the cloud-world flow through a positively curved early bulk demonstrates the fast orbital speed of outer stars owing to external fields exerted on galaxies as they have travelled through conformally curved spacetimes. These findings could elucidate the fast orbital speed of outer stars in galaxies while the formation of a galaxy and its core simultaneously could explain the supermassive compact galaxy core growth to a mass of ~10⁹ M_⊙ at just 6% of the current Universe age.