I’m having the same issue on my iPad Pro, v14.0.1, TV control app v4.5.1
If I try to watch one of my recorded shows, it tells me out of home streaming is not permitted. If I press the remote icon, it tells me the selected Virgin Tv box was not found on the current network. I’ve checked my V6 box is on the same SSID as my iPad and on the same subnet. I’ve reset the app, deleted and re-installed it to no avail. The necessary permission to allow the app access to my local network is set.
My Android phone on the same network has no problem using the TV Control app at all.