We have a couple of 3910's using IKEv2 for Dial-in VPN users (as we found it best for performance by far).
However we can only get it to work by using the DrayDDNS service and the Lets Encrypt certificate it requests and installs itself.
Tried with GoDaddy and the SmartVPN won't connect even with the certificate selected in the correct places on the 3910.
Has anyone had success with anything other than the built in Lets Encrypt?