What to Check After Changing Your Nameservers
https://rapid-wiki.win/index.php/What_to_Check_After_Changing_Your_Nameservers
After you update your nameservers, it typically takes a few hours to 48 hours for DNS changes to propagate worldwide. During this window, some visitors may still see your old site while others see the new one. You can verify propagation using online DNS checkers, and confirm your domain resolves to the correct IP address. Also test email delivery if you changed mail records, and ensure SSL certificates are valid for the new host. Patience is key—propagation is not instant.