When the problem is your machine.
WHEN THIS APPLIES
Everyone else sees the change and you do not.
Or you tested a site with a hosts file entry and forgot to remove it.
WHAT CACHES DNS LOCALLY
Your operating system Your browser, separately Your router, sometimes Your internet provider's resolver
FLUSHING THE OPERATING SYSTEM CACHE
Each system has its own command. Searching for the command for your version gives it.
BROWSERS
Some cache DNS independently. A private window usually bypasses it, and restarting the browser certainly does.
CHECK THE HOSTS FILE
If you added an entry to test a migration, it overrides DNS entirely.
Forgetting to remove it means you continue seeing the old server indefinitely while everyone else sees the new one.
This is a genuinely common and confusing self-inflicted problem.
THE QUICKEST TEST
Mobile data, with wifi off. Different network, different resolver, no local cache.
If it works there, the problem is local.
WHAT NOT TO DO
Conclude a change failed based on your own machine alone.
