Most of what breaks a business website happens somewhere other than the website. Check who actually controls the domain, whether certificate renewal is automated or sitting in someone's calendar reminder, whether anyone receives the form submissions today, whether your backups have ever been restored, and whether one person is the only one who can deploy a change.
Four of those five live in accounts and processes, not in pages, which is why a site can look perfect the day it quietly stops working. We'd guess one of the five would take you much longer to answer with certainty than the other four.