After research I found that alot of people facing the same issue. But so far I don\'t solution, this happened after I switch my server to linode.com
lets take an exa
i found the solution at last.
In my default DNS A/AAAA record i did not remove these few ip
2400:8900::f03c:91ff:fe73:a95d Default
mail 2400:8900::f03c:91ff:fe73:a95d Default
www 2400:8900::f03c:91ff:fe73:a95d Default
that's why some of the users will pointed to the above IP when they access via proper web address.