Server Certificate error after router IP change

[nedj10]

I am running OpenVpn 2.4.4 on Ubuntu 18.04 I just upgraded internet service which came with a new router, the new router has a different public Ip address from the previous router, so I updated the IP in my client ovpn file and then deleted the old profile and added a new one with the new file on one client. After doing this the client rejects connection stating there is an error with the server certificate. -

Is there an easy way to update the server certifcate and then redeploy client files with the new cert?

Thanks,
Ned