Hi Chelle53 👋 Welcome to the community forum! Thanks for joining and making your first post.
Sorry to hear you are having some difficulties with managing your child's connection access.
There's an article which may provide a bit of help and insight here 👉 https://www.virginmedia.com/help/security/parental-controls
If pausing the connection isn't doing the trick, the only other way would be to block the devices connection in your advanced settings via your Hub.
Head to 👉 https://www.virginmedia.com/help/broadband/set-up-broadband and the section titled 'How to configure advanced settings on the Hub' to see how to access your advanced settings. Once there, you can head to 'Advanced Settings' > 'Security' > Wireless Mac Filtering, and you can filter the connection to that device via Wi-Fi. I'd recommend updating the advanced hub settings to something your child does not know, so they can't access it. You would need to this process manually every time you want to turn the filter off and on. (And won't stop the connection via Ethernet!)
For a bit more context - Ethernet provides broadband connection via cable. His PC would work for any non-internet functionality without a broadband connection. In terms of using his broadband connection for gaming with Wi-Fi instead of ethernet, it may affect the quality of his online gaming - but, you can't stop his broadband connection if he is connected via Ethernet.
It's also worth pointing out that this information is readily available online, and he sounds like a smart kid - so may be aware of all of this too!
Hope this helps 🤞 feel free to let us know how you get on. Best of luck! 🌞