A radio, optical, UV and X-ray view of the enigmatic changing look
  Active Galactic Nucleus 1ES~1927+654 from its pre- to post-flare states
  The nearby type-II AGN 1ES1927+654 went through a violent changing-look (CL)
event beginning December 2017 during which the optical and UV fluxes increased
by four magnitudes over a few months, and broad emission lines newly appeared
in the optical/UV. By July 2018 the X-ray coronal emission had completely
vanished, only to reappear a few months later. In this work we report the
evolution of the radio, optical, UV and X-rays from the pre-flare state through
mid-2021 with new and archival data from the Very Long Baseline Array (VLBA),
the European VLBI Network, the Very Large Array (VLA), the Telescopio Nazionale
Galileo (TNG), Gran Telescopio Canarias (GTC), The Neil Gehrels Swift
observatory and XMM-Newton. The main results from our work are: (1) The source
has returned to its pre-CL state in optical, UV, and X-ray; the disk-corona
relation has been re-established as has been in the pre-CL state, with an
$\alpha_{\rm OX}\sim 1.02$. The optical spectra are dominated by narrow
emission lines. (2) The UV light curve follows a shallower slope of $\propto
t^{-0.91\pm 0.04}$ compared to that predicted by a tidal disruption event. We
conjecture that a magnetic flux inversion event is the possible cause for this
enigmatic event. (3) The compact radio emission which we tracked in the pre-CL
(2014), during CL (2018) and post-CL(2021) at spatial scales $<1$ pc was at its
lowest level during the changing look event in 2018, nearly contemporaneous
with a low $2-10$ keV emission. The radio to X-ray ratio of the compact source
$L_{\rm Radio}/L_{\rm X-ray}\sim 10^{-5.5}$, follows the Gudel-Benz relation,
typically found in coronally active stars, and several AGN. (4) We do not
detect any presence of nascent jets at the spatial scales of $\sim 5-10$ pc.
