New router Synology NAS not found.

[mors]

My Superhub 2 died overnight on Friday.I set up a Superhub 3 yesterday but since set up my Synology 718+ has not been recognised.I've tried a NAS reset but that did not help.I've also tried to open Synology Assistant but no server found Minimwatch is also greyed out.Any help that anybody could give would be much appreciated.