Internet not working (Sky fibre)

Hello hopefully someone on here can help me as sky can't.

So four days ago all was fine and dandy I was on he Internet watching Sky go and it just went off. Since then I have had no internet connection. I can't go on any webpage. Tried on phone and on iPad. Xbox doesn't work. And wired using Ethernet with laptop does not work either. Sky and bt have tested the line and all is fine. They said must be the router. So I got a new one and exactly the same. When I do all the checks on the router which they ask me all comes back fine. They have escalated it again but will take 5 days. It does not let me go on the speedtest website as it just won't load. But I have the app and the results are.
Ping 27
Download 0.01 Mbps
Upload 19.99 Mbps

I just don't get why everything else is fine apart from my download. It's like it starts at 50mbps for a millisecond then just drops to 0.01 at the end. I just don't get it. Tried 100 of websites and nothing will load. No apps etc apart from one thing. I use FaceTime and works fine. No problem 100% clear connection. I just don't get it. Sky says no bars or restrictions or anything on the account. On the sky page when I 192.168.0.1 says the router is getting 59mbps but I can't go on anything or use any internet at all.

Sorry it's long winded just wanted to give as much info as possible. Also I apologise for any grammar spelling mistakes I'm on my phone and it's awkward :/

Any more info needed just ask and thanks in advance. Hopefully someone can help and no one at sky seems to know what's going on and just telling me it's working.

Thanks again 😃