DNS Resolve Issue or Error

i have a problem regarding the DNS. I had a dedicated server running in Cpanel for the last 5 Yrs. and its DNS is ns1.mydomain.com(IP: 22.22.22.22) and ns2.mydomain.com(IP 33.33.33.33). i successfully migrated all the domains and accounts to a new Cpanel server and changed the name servers IP. ns1 IP changed to 44.44.44.44 and ns2 changed to 55.55.55.55 Now 3 months completed. Still, some domains' IPs show old IPs in intodns and DNS leaf. How can resolve it correctly? Please help. All the IP and domain mentioned here is dummy