"macOS" has a tendency to cache stale DNS. But over the years they have changed the commands to flush the cache, so you end up googling how to clear the cache,

"macOS" has a tendency to cache stale DNS. But over the years they have changed the commands to flush the cache, so you end up googling how to clear the cache, checking your version of osx, and pray to the DNS gods that it will work this time.