There's no shortage of 'how to' info via a Google search on
virgin media powerline instructions
Have you tried following some of the the guides from a search?
Two further things to consider might be that ...
The Hub 5 uses the latest wireless AX standard and that may be causing an issue with the old VM powerline devices trying to connect.
Secondly the VM powerline devices are regularly mentioned on here after they have experienced a 'thermal event'. As you have switched to a new hub with the newest wi-fi standard you might want to consider whether to reinstate the old VM powerlines or not. Personally speaking the old VM powerlines are not something I would have running 24/7 in my own home.
