Can a puthujjana have unshakable faith in the Buddha-Dhamma? I read the following on the internet:

According to my present understanding of Dhamma, nobody will be able
to shake my faith.

Can a puthujjana (unenlightened commoner still immersed in self instinct) have unshakable faith in the Buddha-Dhamma?
What happens if a puthujjana does a meditation retreat and freaks out when in solitude or experiencing ego-death?
What are the conditions or criteria for unshakable faith (acalā saddha)?
Right view arises with two conditions:

AN2.126:1.1: “There are two conditions for the arising of right view.  What two? The words of another and proper attention.  These are the two conditions for the arising of right view.”

Unshakeable faith happens thus:

MN106:13.3: But sir, what is noble liberation?”  “Ananda, it’s when a mendicant reflects like this: ‘Sensual pleasures in this life and in lives to come, sensual perceptions in this life and in lives to come, visions in this life and in lives to come, perceptions of visions in this life and in lives to come, perceptions of the imperturbable, perceptions of the dimension of nothingness, perceptions of the dimension of neither perception nor non-perception; that is identity as far as identity extends. This is the deathless, namely the liberation of the mind through not grasping.

Importantly, &quot;perceptions of the imperturbable&quot; are also identity and to be relinquished without grasping. So declaring &quot;I am imperturbable&quot; misses the mark. Better to just walk while walking and just stand while standing.
Decades ago I went to a retreat, perceived non-self and freaked out. That was definitely unpleasant, but it was an important clue about the Noble Truths. It's taken a lifetime to muster proper attention and find the words of another. With proper attention and the words of another, one can have faith that the Noble Eightfold Path will give rise to unshakeable faith upon release from all the fetters.