So this email arrived today from DrayTeK and seems DrayTeK are Upgrading there Systems including MyVigor.
Email seems genuine but I still need to investigate further.
At DrayTek, your network security is of upmost importance to us, so we continually work at providing improvements. We do this by releasing updated firmware with security enhancements for all Vigor products, including updates to the MyVigor server.
We are in the process upgrading the system architecture for MyVigor, your devices will need to be upgraded to be compatible with the new system. We therefore require your help to complete the upgrade process by following the steps below. These steps need to be completed within 60 days or the WCF and DrayDDNS services may not work as expected after 2021-05-22.
In a completely sane world, madness is the only freedom (J.G.Ballard).