  Following the high activity of the gamma-ray Fermi source 4FGL J0449.1+1121
(PKS 0446+112), possibly associated with a IceCube neutrino event IC-240105A,
we obtained optical spectroscopy with the Gran Telescopio Canarias of the
counterpart. We detect a clear emission line at 3830 Ang identified as
Ly$\alpha$ that confirms the redshift of source at z=2.153. Comparing with
previous spectroscopy, we find an increase of the continuum by a factor
$\sim$10, and a significant decrease of the CIV 1550 emission line flux by a
factor $\sim$5. This produces a dramatic drop of the Equivalent Width from
$\sim$20 Ang to 0.8 Ang, which is suggestive of a very high jet activity. The
Full Width Half Maximum of the emission lines are midway (1000 - 2000 km/s)
between those typical of the broad and narrow regions of quasars. Based on
this, the source classification is intermediate between Flat Spectrum Radio
Quasar and BL Lac object.
