As indicated the VM engineer turned up last Friday and listened to all my issues, and understood what I was saying about the HUB 5 not automatically picking up any 2.4Ghz connections. What they suggested was dropping back down to a HUB 4.
This was installed and I set-up exactly as I needed and immediately once this was done ALL devices on the 5Ghz channel and 2,4Ghz channel connected and the devices started working. We concluded that the HUB 5 technology (wifi 6) was too advanced and complicated for some of the older devices in the house.
If anyone else has similar issues when uprading to a HUB 5, please try and get a technician to downgrade to HUB 4 - otherwise you will get a continuation of 'Unable to obtain an IP address' when trying to connect.