The SOA MNAME entry can not be modified when the DNS server is changed.
Where is the road to organize?
You can register new IPs at domain registrar?
yes, ns server looks but SOA MNAME others see old ns
You may want to give it some time to propagate globally.
any news for the SOA??
as i always get
SOA Serial Number Format is Invalid
SOA Expire Value out of recommended range