====== How to Flush DNS Cache ======
Your (upstream) router or domain controller is likely caching DNS queries you make. You might have to flush the DNS caches in one of those devices before you get the desired results.
===== Windows =====
ipconfig /flushdns
===== SME Server =====
signal-event dns-update
===== Linux =====
Depending on your system, one of these might work:
sudo systemctl restart nscd
sudo systemctl restart dnsmasq
rndc flush
===== Ubuntu =====
sudo systemd-resolve --statistics
sudo systemd-resolve --flush-caches