Due to its brightness and proximity, the radio galaxy 3C 84 (optical counterpart: NGC 1275 in the Perseus cluster) has been the target for extensive studies to investigate the central parsec region of its active galactic nucleus. In 2003, its most recent active phase resulted in a plasma ejection visible in the southern jet, which presented a unique opportunity to study jet formation and evolution at high angular resolution with very long baseline interferometry (VLBI). We aim to study the morphology, evolution and spectral properties of the restarted jet three years after the first ultra-high angular resolution observations with the RadioAstron space-VLBI satellite in September 2013. We use space-VLBI observations carried out in September 2016 at 22GHz with a global VLBI network and the 10-m Spektr-R radio telescope in orbit, as well as quasi-simultaneous multi-frequency observations at 4.8, 8, 15, and 43GHz from the Very Long Baseline Array (VLBA), including the Effelsberg 100-m telescope, to study 3C 84. Here we present the 22GHz RadioAstron image of 3C 84 from 2016, which reveals the source's central region at a 58{mu}as effective resolution. During the three years that elapsed between the first and second space-VLBI observations, the source has undergone significant morphological changes. We confirm the existence of the limb-brightened jet and counter-jet reported earlier, as well as a flip in the position of the hotspot discovered recently via KaVA monitoring at 43GHz. Upon measuring the collimation profile, we find that it has evolved from quasi-cylindrical to parabolic. This is most likely the result of the decreased pressure of the mini-cocoon, which was inflated by the jet and contains hot gas, that cannot confine the jet efficiently as it propagates further away from the core. Finally, we also constrain the magnetic field strength in the core region and the hotspot.

Cone search capability for table J/A+A/709/A226/list (List of fits maps)