Devolo Magic 2 network not working with Hub 5

Hi, everyone

Up until a couple of weeks ago, I had been running a happy wifi network using Devolo Magic 2 Powerline/Mesh and a VM Hub 3 for a couple of years. Then we started getting frequent problems with internet access, requiring the Hub to be reset/rebooted several times a day. Spoke with VM, who advised me to upgrade to a faster service and a Hub 5 which they duly dispatched. Still problems so I requested an engineer visit. He found several small issues with the Virgin cabling and ports which he corrected.

Now we have stable TV and Hub, but I can't get the Devolo network to run. It doesn't seem to recognise the Hub. I wondered whether this was an issue between the older Devolos and a Wifi 6 Hub but, in theory all wifi 6 equipment is back-compatible with earlier equipment. I see from looking back at the Forum, that several people have reported this issue over the past couple of years. No-one seems to have received a proper answer from VM (or Devolo). Do I just give up and buy a Wifi 6 mesh network, or is there something that I can do to make my present setup work?

Just for completeness, the only thing that has changed is the Hub......all Devolo devices have been reset to factory default and then re-bound. the Devolo app tells me that all devices are linked to each other and to the Hub. So why doesn't it work?