Changing Domain Gateway causes very slow login to Domain Controller

Anyone;

I have a small domain with one Domain Controller. Everything is working fine right now, but I am trying to change out my Gateway/router. I am giving the new one the same IP as the old one, but when I put the new one into the network, it takes approx10-15 minutes to login, or use any resources.

I never have both on the network at the same time, and I have flushed and re-registered the DNS, but nothing changes.

When I do get logged into the DC, and I select to look at GPO Manager, it says it cannot resolve the Domain Name. I’ve looked at records and IP settings and I can’t see anything wrong.

Any assistance would be greatly appreciated.

Thank you in advance.

Ray