The cosmic microwave background (CMB) temperature and polarization anisotropies, as
observed by independent astronomical missions such as WMAP, Planck, and most recently the Atacama
Cosmology Telescope and the South Pole Telescope have played a vital role in accurately
constraining cosmological theories and models, establishing cosmic inflation as the most widely
accepted theory for describing the physics of the early Universe. However, the absence of a
definitive detection of B-mode polarization and the emerging discrepancies among different CMB
experiments present a challenge in determining which inflationary models best explain the observed
data. In this work, we further explore this difficulty and conduct a case study by analyzing four
well-known inflationary potentials in light of the latest CMB temperature and polarization
anisotropy measurements and lensing data released by the Planck satellite and the Atacama
Cosmology Telescope. Additionally, we incorporate B-modes polarization data from the BICEP/Keck
Collaboration, as well as Baryon Acoustic Oscillations and Redshift Space Distortions measurements
from BOSS DR12 and eBOSS DR16. We show that the most typical models such as Starobinsky and
α-attractors are in disagreement with the Atacama Cosmology Telescope small-scale CMB
measurements, particularly when combined with B-modes polarization data. On the other hand, these
potentials are in perfect agreement with the Planck measurements at larger angular scales. This
dichotomy makes it challenging to identify a single model or a group of models that can be
universally considered as the preferred choice based on all available CMB observations.