Tried emptying the cache: have reinstalled a couple of times on my Android device; tried installing the Microsoft Store version of the app on my laptop; same issue every time. I can log in, see the channels, but when I try to watch any, it says it is unavailable- error code 241.
I'll try the app again in a week or two. For now I'm happy with what I've got. Yesterday evening the whole system went down - broadband and tv - for a couple of hours, so what I have now is a big improvement!
If you can see La Liga TV on your TV via your Virgin box then it should be available on TV Go. Try a refresh of the channel list. Failing that try reinstalling the app. If still no joy, then it's a call to Virgin I guess.