See my following testing with Pauli matrices defined by different sympy modules:
In [57]: init_printing(wrap_line=False)
...: from sympy.physics.paulialgebra import Pauli
...: from sympy.physics.matrices import msigma
In [58]: Pauli(1) == msigma(1)
Out[58]: False
Why can’t the same Pauli matrices defined by different modules be considered the same?
As far as I understand from Pauli Algebra — SymPy 1.8 documentation (and the source code at sympy/paulialgebra.py at master · sympy/sympy · GitHub), Pauli matrices as implemented by sympy.physics.paulialgebra are purely symbolic. The class is derived from Symbol. So there are three unique values, with operations between them, but no interface linking them with matrices (but that is my understanding; you may want to ask on a Sympy-specific forum as Dominik proposed, such as https://groups.google.com/g/sympy).