The only thing I can think of is the domain hits some kind of ages old tiny trickle threshold for data/traffic to the site...where exorbitant charges get applied, or the site goes dark for triggering things.
So many other hosting places no longer do that for a tiny monthly charge nowadays.
That said, if being hosted on a friend of a friend’s server - time to get rid of it, or that relationship as it shows a level of mediocrity for an online business-based model.