Engineer said there was a lot of problems causing it so couldn't really give me an exact answer. I think there was a major issue at the street cabinet in my area where my fibre connection goes. The guy who installed it must have done it completely wrong and messed something up big time.
Funny how the other 2 engineers missed that though
They both claimed it was fine and all working as normal so must be the router. Obviously not..
.
If I wasn't so tired, I'd try to fix it. But I cba, I'm on RS, I can browse the internet (just about) and all of my music on Spotify is available offline so it's fine.