  The recent observations from the James Webb Space Telescope have led to a
surprising discovery of a significant density of massive galaxies with masses
of $M \ge 10^{10.5} M_{\odot}$ at redshifts of approximately $z\sim 10$. This
corresponds to a stellar mass density of roughly $\rho_*\sim 10^6 M_{\odot}
Mpc^{-3}$. Despite making conservative assumptions regarding galaxy formation,
this finding may not be compatible with the standard $\Lambda$CDM cosmology
that is favored by observations of CMB Anisotropies from the Planck satellite.
In this paper, we confirm the substantial discrepancy with Planck's results
within the $\Lambda$CDM framework. Assuming a value of $\epsilon=0.2$ for the
efficiency of converting baryons into stars, we indeed find that the
$\Lambda$CDM model is excluded at more than $99.7 \%$ confidence level (C.L.).
An even more significant exclusion is found for $\epsilon \sim 0.1$, while a
better agreement, but still in tension at more than $95 \%$, is obtained for
$\epsilon =0.32$. This tension, as already discussed in the literature, could
arise either from systematics in the JWST measurements or from new physics.
Here, as a last-ditch effort, we point out that disregarding the large angular
scale polarization obtained by Planck, which allows for significantly larger
values of the matter clustering parameter $\sigma_8$, could lead to better
agreement between Planck and JWST within the $\Lambda$CDM framework.
Interestingly, the model compatible with Planck temperature-only data and JWST
observation also favors a higher Hubble constant $H_0=69.0\pm1.1$ km/s/Mpc at
$68\%$ C.L., in better agreement with observations based on SN-Ia luminosity
distances.

Cosmology and Nongalactic Astrophysics;High Energy Physics - Phenomenology