Discovery +says I'm not connected to the internet but but I am how do I fix it?

[Hayden+Fischer]

I can't watch discovery + on my sky Q box it says I'm not connected to the internet but I am. My sky Q box is connected as are all other apps are connected as.

What do I do to fix this, please? 

[heatherjayne]

Mine is the same been like it all afternoon. Switched off the box but it didn't make any difference. 
Hope it's sorted soon as my husband loves watching programs on it.